RUST GYM Rust Solutions

Leetcode Solutions in Rust

AdventOfCode Solutions in Rust

Google Solutions in Rust

This project demonstrates how to create Data Structures and to implement Algorithms using programming language Rust All the solutions here are crafted with love and their performance beats 99% of other solutions on the leetcode website. Tutorial videos will be added later.

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Data Structures

• Stack & Queue ( Vec, VecDeque )
• Linked List ( Option<Box> )
• Hash Tables ( HashMap, HashSet )
• Tree Tables ( BTreeMap, BTreeSet )
• Binary Search Tree ( Option<Rc<RefCell>> )
• Binary Heaps & Priority Queue ( BinaryHeap )
• Graphs ( Vec<Vec> )
• Union Find ( UnionFind )
• Trie ( Trie )

Algorithms

• Bit Manipulation & Numbers
• Stability in Sorting
• Heapsort
• Binary Search
• Kth Smallest Elements
• Permutations
• Subsets
• BFS Graph
• DFS Graph
• Dijkstra’s Algorithm
• Tree Traversals
  • BFS
  • DFS
    • in-order
    • pre-order
    • post-order
• Topological Sort
• Detect cycle in an undirected graph
• Detect a cycle in a directed graph
• Count connected components in a graph
• Find strongly connected components in a graph

id	Leetcode	Level
1	Two Sum	Easy
9	Palindrome Number	Easy
13	Roman to Integer	Easy
14	Longest Common Prefix	Easy
20	Valid Parentheses	Easy
21	Merge Two Sorted Lists	Easy
26	Remove Duplicates from Sorted Array	Easy
27	Remove Element	Easy
28	Implement strStr()	Easy
35	Search Insert Position	Easy
53	Maximum Subarray	Easy
58	Length of Last Word	Easy
66	Plus One	Easy
67	Add Binary	Easy
69	Sqrt(x)	Easy
70	Climbing Stairs	Easy
83	Remove Duplicates from Sorted List	Easy
88	Merge Sorted Array	Easy
94	Binary Tree Inorder Traversal	Easy
100	Same Tree	Easy
101	Symmetric Tree	Easy
104	Maximum Depth of Binary Tree	Easy
108	Convert Sorted Array to Binary Search Tree	Easy
110	Balanced Binary Tree	Easy
111	Minimum Depth of Binary Tree	Easy
112	Path Sum	Easy
118	Pascal's Triangle	Easy
119	Pascal's Triangle II	Easy
121	Best Time to Buy and Sell Stock	Easy
125	Valid Palindrome	Easy
136	Single Number	Easy
141	Linked List Cycle	Easy
144	Binary Tree Preorder Traversal	Easy
145	Binary Tree Postorder Traversal	Easy
155	Min Stack	Easy
157	Read N Characters Given Read4	Easy
160	Intersection of Two Linked Lists	Easy
163	Missing Ranges	Easy
167	Two Sum II - Input Array Is Sorted	Easy
168	Excel Sheet Column Title	Easy
169	Majority Element	Easy
170	Two Sum III - Data structure design	Easy
171	Excel Sheet Column Number	Easy
190	Reverse Bits	Easy
191	Number of 1 Bits	Easy
202	Happy Number	Easy
203	Remove Linked List Elements	Easy
205	Isomorphic Strings	Easy
206	Reverse Linked List	Easy
217	Contains Duplicate	Easy
219	Contains Duplicate II	Easy
225	Implement Stack using Queues	Easy
226	Invert Binary Tree	Easy
228	Summary Ranges	Easy
231	Power of Two	Easy
232	Implement Queue using Stacks	Easy
234	Palindrome Linked List	Easy
235	Lowest Common Ancestor of a Binary Search Tree	Easy
237	Delete Node in a Linked List	Easy
242	Valid Anagram	Easy
243	Shortest Word Distance	Easy
246	Strobogrammatic Number	Easy
252	Meeting Rooms	Easy
257	Binary Tree Paths	Easy
258	Add Digits	Easy
263	Ugly Number	Easy
266	Palindrome Permutation	Easy
268	Missing Number	Easy
270	Closest Binary Search Tree Value	Easy
278	First Bad Version	Easy
283	Move Zeroes	Easy
290	Word Pattern	Easy
292	Nim Game	Easy
293	Flip Game	Easy
303	Range Sum Query - Immutable	Easy
326	Power of Three	Easy
338	Counting Bits	Easy
342	Power of Four	Easy
344	Reverse String	Easy
345	Reverse Vowels of a String	Easy
346	Moving Average from Data Stream	Easy
349	Intersection of Two Arrays	Easy
350	Intersection of Two Arrays II	Easy
359	Logger Rate Limiter	Easy
367	Valid Perfect Square	Easy
374	Guess Number Higher or Lower	Easy
383	Ransom Note	Easy
387	First Unique Character in a String	Easy
389	Find the Difference	Easy
392	Is Subsequence	Easy
401	Binary Watch	Easy
404	Sum of Left Leaves	Easy
405	Convert a Number to Hexadecimal	Easy
408	Valid Word Abbreviation	Easy
409	Longest Palindrome	Easy
412	Fizz Buzz	Easy
414	Third Maximum Number	Easy
415	Add Strings	Easy
422	Valid Word Square	Easy
434	Number of Segments in a String	Easy
441	Arranging Coins	Easy
448	Find All Numbers Disappeared in an Array	Easy
455	Assign Cookies	Easy
459	Repeated Substring Pattern	Easy
461	Hamming Distance	Easy
463	Island Perimeter	Easy
476	Number Complement	Easy
482	License Key Formatting	Easy
485	Max Consecutive Ones	Easy
492	Construct the Rectangle	Easy
495	Teemo Attacking	Easy
496	Next Greater Element I	Easy
500	Keyboard Row	Easy
501	Find Mode in Binary Search Tree	Easy
504	Base 7	Easy
506	Relative Ranks	Easy
507	Perfect Number	Easy
509	Fibonacci Number	Easy
520	Detect Capital	Easy
521	Longest Uncommon Subsequence I	Easy
530	Minimum Absolute Difference in BST	Easy
541	Reverse String II	Easy
543	Diameter of Binary Tree	Easy
551	Student Attendance Record I	Easy
557	Reverse Words in a String III	Easy
559	Maximum Depth of N-ary Tree	Easy
561	Array Partition I	Easy
563	Binary Tree Tilt	Easy
566	Reshape the Matrix	Easy
572	Subtree of Another Tree	Easy
575	Distribute Candies	Easy
589	N-ary Tree Preorder Traversal	Easy
590	N-ary Tree Postorder Traversal	Easy
594	Longest Harmonious Subsequence	Easy
598	Range Addition II	Easy
599	Minimum Index Sum of Two Lists	Easy
604	Design Compressed String Iterator	Easy
605	Can Place Flowers	Easy
606	Construct String from Binary Tree	Easy
617	Merge Two Binary Trees	Easy
628	Maximum Product of Three Numbers	Easy
637	Average of Levels in Binary Tree	Easy
643	Maximum Average Subarray I	Easy
645	Set Mismatch	Easy
653	Two Sum IV - Input is a BST	Easy
657	Robot Return to Origin	Easy
661	Image Smoother	Easy
671	Second Minimum Node In a Binary Tree	Easy
674	Longest Continuous Increasing Subsequence	Easy
680	Valid Palindrome II	Easy
682	Baseball Game	Easy
693	Binary Number with Alternating Bits	Easy
696	Count Binary Substrings	Easy
697	Degree of an Array	Easy
700	Search in a Binary Search Tree	Easy
703	Kth Largest Element in a Stream	Easy
704	Binary Search	Easy
705	Design HashSet	Easy
706	Design HashMap	Easy
709	To Lower Case	Easy
716	Max Stack	Easy
717	1-bit and 2-bit Characters	Easy
724	Find Pivot Index	Easy
728	Self Dividing Numbers	Easy
733	Flood Fill	Easy
734	Sentence Similarity	Easy
744	Find Smallest Letter Greater Than Target	Easy
746	Min Cost Climbing Stairs	Easy
747	Largest Number At Least Twice of Others	Easy
748	Shortest Completing Word	Easy
760	Find Anagram Mappings	Easy
762	Prime Number of Set Bits in Binary Representation	Easy
766	Toeplitz Matrix	Easy
771	Jewels and Stones	Easy
783	Minimum Distance Between BST Nodes	Easy
796	Rotate String	Easy
800	Similar RGB Color	Easy
804	Unique Morse Code Words	Easy
806	Number of Lines To Write String	Easy
812	Largest Triangle Area	Easy
819	Most Common Word	Easy
821	Shortest Distance to a Character	Easy
824	Goat Latin	Easy
830	Positions of Large Groups	Easy
832	Flipping an Image	Easy
836	Rectangle Overlap	Easy
844	Backspace String Compare	Easy
852	Peak Index in a Mountain Array	Easy
859	Buddy Strings	Easy
860	Lemonade Change	Easy
867	Transpose Matrix	Easy
868	Binary Gap	Easy
872	Leaf-Similar Trees	Easy
876	Middle of the Linked List	Easy
883	Projection Area of 3D Shapes	Easy
884	Uncommon Words from Two Sentences	Easy
888	Fair Candy Swap	Easy
892	Surface Area of 3D Shapes	Easy
896	Monotonic Array	Easy
897	Increasing Order Search Tree	Easy
905	Sort Array By Parity	Easy
908	Smallest Range I	Easy
914	X of a Kind in a Deck of Cards	Easy
917	Reverse Only Letters	Easy
922	Sort Array By Parity II	Easy
925	Long Pressed Name	Easy
929	Unique Email Addresses	Easy
933	Number of Recent Calls	Easy
937	Reorder Data in Log Files	Easy
938	Range Sum of BST	Easy
941	Valid Mountain Array	Easy
942	DI String Match	Easy
944	Delete Columns to Make Sorted	Easy
953	Verifying an Alien Dictionary	Easy
961	N-Repeated Element in Size 2N Array	Easy
965	Univalued Binary Tree	Easy
976	Largest Perimeter Triangle	Easy
977	Squares of a Sorted Array	Easy
989	Add to Array-Form of Integer	Easy
993	Cousins in Binary Tree	Easy
997	Find the Town Judge	Easy
999	Available Captures for Rook	Easy
1002	Find Common Characters	Easy
1005	Maximize Sum Of Array After K Negations	Easy
1009	Complement of Base 10 Integer	Easy
1013	Partition Array Into Three Parts With Equal Sum	Easy
1018	Binary Prefix Divisible By 5	Easy
1021	Remove Outermost Parentheses	Easy
1022	Sum of Root To Leaf Binary Numbers	Easy
1025	Divisor Game	Easy
1030	Matrix Cells in Distance Order	Easy
1037	Valid Boomerang	Easy
1046	Last Stone Weight	Easy
1047	Remove All Adjacent Duplicates In String	Easy
1051	Height Checker	Easy
1056	Confusing Number	Easy
1064	Fixed Point	Easy
1065	Index Pairs of a String	Easy
1071	Greatest Common Divisor of Strings	Easy
1078	Occurrences After Bigram	Easy
1085	Sum of Digits in the Minimum Number	Easy
1086	High Five	Easy
1089	Duplicate Zeros	Easy
1099	Two Sum Less Than K	Easy
1103	Distribute Candies to People	Easy
1108	Defanging an IP Address	Easy
1114	Print in Order	Easy
1118	Number of Days in a Month	Easy
1119	Remove Vowels from a String	Easy
1122	Relative Sort Array	Easy
1128	Number of Equivalent Domino Pairs	Easy
1133	Largest Unique Number	Easy
1134	Armstrong Number	Easy
1137	N-th Tribonacci Number	Easy
1150	Check If a Number Is Majority Element in a Sorted Array	Easy
1154	Day of the Year	Easy
1160	Find Words That Can Be Formed by Characters	Easy
1165	Single-Row Keyboard	Easy
1175	Prime Arrangements	Easy
1176	Diet Plan Performance	Easy
1180	Count Substrings with Only One Distinct Letter	Easy
1184	Distance Between Bus Stops	Easy
1185	Day of the Week	Easy
1189	Maximum Number of Balloons	Easy
1196	How Many Apples Can You Put into the Basket	Easy
1200	Minimum Absolute Difference	Easy
1207	Unique Number of Occurrences	Easy
1213	Intersection of Three Sorted Arrays	Easy
1217	Minimum Cost to Move Chips to The Same Position	Easy
1221	Split a String in Balanced Strings	Easy
1228	Missing Number In Arithmetic Progression	Easy
1232	Check If It Is a Straight Line	Easy
1243	Array Transformation	Easy
1252	Cells with Odd Values in a Matrix	Easy
1260	Shift 2D Grid	Easy
1266	Minimum Time Visiting All Points	Easy
1271	Hexspeak	Easy
1275	Find Winner on a Tic Tac Toe Game	Easy
1279	Traffic Light Controlled Intersection	Easy
1281	Subtract the Product and Sum of Digits of an Integer	Easy
1287	Element Appearing More Than 25% In Sorted Array	Easy
1290	Convert Binary Number in a Linked List to Integer	Easy
1295	Find Numbers with Even Number of Digits	Easy
1299	Replace Elements with Greatest Element on Right Side	Easy
1304	Find N Unique Integers Sum up to Zero	Easy
1309	Decrypt String from Alphabet to Integer Mapping	Easy
1313	Decompress Run-Length Encoded List	Easy
1317	Convert Integer to the Sum of Two No-Zero Integers	Easy
1323	Maximum 69 Number	Easy
1331	Rank Transform of an Array	Easy
1332	Remove Palindromic Subsequences	Easy
1337	The K Weakest Rows in a Matrix	Easy
1342	Number of Steps to Reduce a Number to Zero	Easy
1346	Check If N and Its Double Exist	Easy
1351	Count Negative Numbers in a Sorted Matrix	Easy
1356	Sort Integers by The Number of 1 Bits	Easy
1360	Number of Days Between Two Dates	Easy
1365	How Many Numbers Are Smaller Than the Current Number	Easy
1370	Increasing Decreasing String	Easy
1374	Generate a String With Characters That Have Odd Counts	Easy
1380	Lucky Numbers in a Matrix	Easy
1385	Find the Distance Value Between Two Arrays	Easy
1389	Create Target Array in the Given Order	Easy
1394	Find Lucky Integer in an Array	Easy
1399	Count Largest Group	Easy
1403	Minimum Subsequence in Non-Increasing Order	Easy
1408	String Matching in an Array	Easy
1413	Minimum Value to Get Positive Step by Step Sum	Easy
1417	Reformat The String	Easy
1422	Maximum Score After Splitting a String	Easy
1426	Counting Elements	Easy
1427	Perform String Shifts	Easy
1431	Kids With the Greatest Number of Candies	Easy
1436	Destination City	Easy
1437	Check If All 1's Are at Least Length K Places Away	Easy
1441	Build an Array With Stack Operations	Easy
1446	Consecutive Characters	Easy
1450	Number of Students Doing Homework at a Given Time	Easy
1455	Check If a Word Occurs As a Prefix of Any Word in a Sentence	Easy
1460	Make Two Arrays Equal by Reversing Sub-arrays	Easy
1464	Maximum Product of Two Elements in an Array	Easy
1469	Find All The Lonely Nodes	Easy
1470	Shuffle the Array	Easy
1474	Delete N Nodes After M Nodes of a Linked List	Easy
1475	Final Prices With a Special Discount in a Shop	Easy
1480	Running Sum of 1d Array	Easy
1486	XOR Operation in an Array	Easy
1491	Average Salary Excluding the Minimum and Maximum Salary	Easy
1496	Path Crossing	Easy
1502	Can Make Arithmetic Progression From Sequence	Easy
1507	Reformat Date	Easy
1512	Number of Good Pairs	Easy
1518	Water Bottles	Easy
1523	Count Odd Numbers in an Interval Range	Easy
1528	Shuffle String	Easy
1534	Count Good Triplets	Easy
1539	Kth Missing Positive Number	Easy
1544	Make The String Great	Easy
1550	Three Consecutive Odds	Easy
1556	Thousand Separator	Easy
1560	Most Visited Sector in a Circular Track	Easy
1566	Detect Pattern of Length M Repeated K or More Times	Easy
1572	Matrix Diagonal Sum	Easy
1576	Replace All ?'s to Avoid Consecutive Repeating Characters	Easy
1582	Special Positions in a Binary Matrix	Easy
1588	Sum of All Odd Length Subarrays	Easy
1592	Rearrange Spaces Between Words	Easy
1598	Crawler Log Folder	Easy
1603	Design Parking System	Easy
1608	Special Array With X Elements Greater Than or Equal X	Easy
1614	Maximum Nesting Depth of the Parentheses	Easy
1619	Mean of Array After Removing Some Elements	Easy
1624	Largest Substring Between Two Equal Characters	Easy
1629	Slowest Key	Easy
1636	Sort Array by Increasing Frequency	Easy
1640	Check Array Formation Through Concatenation	Easy
1646	Get Maximum in Generated Array	Easy
1652	Defuse the Bomb	Easy
1656	Design an Ordered Stream	Easy
1662	Check If Two String Arrays are Equivalent	Easy
1668	Maximum Repeating Substring	Easy
1672	Richest Customer Wealth	Easy
1678	Goal Parser Interpretation	Easy
1684	Count the Number of Consistent Strings	Easy
1688	Count of Matches in Tournament	Easy
1694	Reformat Phone Number	Easy
1700	Number of Students Unable to Eat Lunch	Easy
1704	Determine if String Halves Are Alike	Easy
1708	Largest Subarray Length K	Easy
1710	Maximum Units on a Truck	Easy
1716	Calculate Money in Leetcode Bank	Easy
1720	Decode XORed Array	Easy
1725	Number Of Rectangles That Can Form The Largest Square	Easy
1732	Find the Highest Altitude	Easy
1736	Latest Time by Replacing Hidden Digits	Easy
1742	Maximum Number of Balls in a Box	Easy
1748	Sum of Unique Elements	Easy
1752	Check if Array Is Sorted and Rotated	Easy
1758	Minimum Changes To Make Alternating Binary String	Easy
1763	Longest Nice Substring	Easy
1768	Merge Strings Alternately	Easy
1773	Count Items Matching a Rule	Easy
1779	Find Nearest Point That Has the Same X or Y Coordinate	Easy
1784	Check if Binary String Has at Most One Segment of Ones	Easy
1790	Check if One String Swap Can Make Strings Equal	Easy
1791	Find Center of Star Graph	Easy
1796	Second Largest Digit in a String	Easy
1800	Maximum Ascending Subarray Sum	Easy
1805	Number of Different Integers in a String	Easy
1812	Determine Color of a Chessboard Square	Easy
1816	Truncate Sentence	Easy
1822	Sign of the Product of an Array	Easy
1826	Faulty Sensor	Easy
1827	Minimum Operations to Make the Array Increasing	Easy
1832	Check if the Sentence Is Pangram	Easy
1837	Sum of Digits in Base K	Easy
1844	Replace All Digits with Characters	Easy
1848	Minimum Distance to the Target Element	Easy
1854	Maximum Population Year	Easy
1859	Sorting the Sentence	Easy
1863	Sum of All Subset XOR Totals	Easy
1869	Longer Contiguous Segments of Ones than Zeros	Easy
1876	Substrings of Size Three with Distinct Characters	Easy
1880	Check if Word Equals Summation of Two Words	Easy
1886	Determine Whether Matrix Can Be Obtained By Rotation	Easy
1893	Check if All the Integers in a Range Are Covered	Easy
1897	Redistribute Characters to Make All Strings Equal	Easy
1903	Largest Odd Number in String	Easy
1909	Remove One Element to Make the Array Strictly Increasing	Easy
1913	Maximum Product Difference Between Two Pairs	Easy
1920	Build Array from Permutation	Easy
1925	Count Square Sum Triples	Easy
1929	Concatenation of Array	Easy
1933	Check if String Is Decomposable Into Value-Equal Substrings	Easy
1935	Maximum Number of Words You Can Type	Easy
1941	Check if All Characters Have Equal Number of Occurrences	Easy
1945	Sum of Digits of String After Convert	Easy
1952	Three Divisors	Easy
1957	Delete Characters to Make Fancy String	Easy
1961	Check If String Is a Prefix of Array	Easy
1967	Number of Strings That Appear as Substrings in Word	Easy
1971	Find if Path Exists in Graph	Easy
1974	Minimum Time to Type Word Using Special Typewriter	Easy
1979	Find Greatest Common Divisor of Array	Easy
1984	Minimum Difference Between Highest and Lowest of K Scores	Easy
1991	Find the Middle Index in Array	Easy
1995	Count Special Quadruplets	Easy
2000	Reverse Prefix of Word	Easy
2006	Count Number of Pairs With Absolute Difference K	Easy
2011	Final Value of Variable After Performing Operations	Easy
2016	Maximum Difference Between Increasing Elements	Easy
2022	Convert 1D Array Into 2D Array	Easy
2027	Minimum Moves to Convert String	Easy
2032	Two Out of Three	Easy
2037	Minimum Number of Moves to Seat Everyone	Easy
2042	Check if Numbers Are Ascending in a Sentence	Easy
2047	Number of Valid Words in a Sentence	Easy
2053	Kth Distinct String in an Array	Easy
2057	Smallest Index With Equal Value	Easy
2062	Count Vowel Substrings of a String	Easy
2068	Check Whether Two Strings are Almost Equivalent	Easy
2073	Time Needed to Buy Tickets	Easy
2078	Two Furthest Houses With Different Colors	Easy
2085	Count Common Words With One Occurrence	Easy
2089	Find Target Indices After Sorting Array	Easy
2094	Finding 3-Digit Even Numbers	Easy
2099	Find Subsequence of Length K With the Largest Sum	Easy
2103	Rings and Rods	Easy
2108	Find First Palindromic String in the Array	Easy
2114	Maximum Number of Words Found in Sentences	Easy
2119	A Number After a Double Reversal	Easy
2124	Check if All A's Appears Before All B's	Easy
2129	Capitalize the Title	Easy
2133	Check if Every Row and Column Contains All Numbers	Easy
2138	Divide a String Into Groups of Size k	Easy
2144	Minimum Cost of Buying Candies With Discount	Easy
2148	Count Elements With Strictly Smaller and Greater Elements	Easy
2	Add Two Numbers	Medium
3	Longest Substring Without Repeating Characters	Medium
5	Longest Palindromic Substring	Medium
6	Zigzag Conversion	Medium
7	Reverse Integer	Medium
8	String to Integer (atoi)	Medium
11	Container With Most Water	Medium
12	Integer to Roman	Medium
15	3Sum	Medium
16	3Sum Closest	Medium
17	Letter Combinations of a Phone Number	Medium
18	4Sum	Medium
19	Remove Nth Node From End of List	Medium
22	Generate Parentheses	Medium
24	Swap Nodes in Pairs	Medium
29	Divide Two Integers	Medium
31	Next Permutation	Medium
33	Search in Rotated Sorted Array	Medium
34	Find First and Last Position of Element in Sorted Array	Medium
36	Valid Sudoku	Medium
38	Count and Say	Medium
39	Combination Sum	Medium
40	Combination Sum II	Medium
43	Multiply Strings	Medium
45	Jump Game II	Medium
46	Permutations	Medium
47	Permutations II	Medium
48	Rotate Image	Medium
49	Group Anagrams	Medium
50	Pow(x, n)	Medium
54	Spiral Matrix	Medium
55	Jump Game	Medium
56	Merge Intervals	Medium
57	Insert Interval	Medium
59	Spiral Matrix II	Medium
61	Rotate List	Medium
62	Unique Paths	Medium
63	Unique Paths II	Medium
64	Minimum Path Sum	Medium
71	Simplify Path	Medium
73	Set Matrix Zeroes	Medium
74	Search a 2D Matrix	Medium
75	Sort Colors	Medium
77	Combinations	Medium
78	Subsets	Medium
79	Word Search	Medium
80	Remove Duplicates from Sorted Array II	Medium
81	Search in Rotated Sorted Array II	Medium
82	Remove Duplicates from Sorted List II	Medium
86	Partition List	Medium
89	Gray Code	Medium
90	Subsets II	Medium
91	Decode Ways	Medium
92	Reverse Linked List II	Medium
93	Restore IP Addresses	Medium
95	Unique Binary Search Trees II	Medium
96	Unique Binary Search Trees	Medium
97	Interleaving String	Medium
98	Validate Binary Search Tree	Medium
99	Recover Binary Search Tree	Medium
102	Binary Tree Level Order Traversal	Medium
103	Binary Tree Zigzag Level Order Traversal	Medium
105	Construct Binary Tree from Preorder and Inorder Traversal	Medium
106	Construct Binary Tree from Inorder and Postorder Traversal	Medium
107	Binary Tree Level Order Traversal II	Medium
109	Convert Sorted List to Binary Search Tree	Medium
113	Path Sum II	Medium
114	Flatten Binary Tree to Linked List	Medium
116	Populating Next Right Pointers in Each Node	Medium
117	Populating Next Right Pointers in Each Node II	Medium
120	Triangle	Medium
122	Best Time to Buy and Sell Stock II	Medium
128	Longest Consecutive Sequence	Medium
129	Sum Root to Leaf Numbers	Medium
130	Surrounded Regions	Medium
131	Palindrome Partitioning	Medium
133	Clone Graph	Medium
134	Gas Station	Medium
137	Single Number II	Medium
138	Copy List with Random Pointer	Medium
139	Word Break	Medium
142	Linked List Cycle II	Medium
143	Reorder List	Medium
146	LRU Cache	Medium
147	Insertion Sort List	Medium
148	Sort List	Medium
150	Evaluate Reverse Polish Notation	Medium
151	Reverse Words in a String	Medium
152	Maximum Product Subarray	Medium
153	Find Minimum in Rotated Sorted Array	Medium
156	Binary Tree Upside Down	Medium
159	Longest Substring with At Most Two Distinct Characters	Medium
161	One Edit Distance	Medium
162	Find Peak Element	Medium
165	Compare Version Numbers	Medium
166	Fraction to Recurring Decimal	Medium
172	Factorial Trailing Zeroes	Medium
173	Binary Search Tree Iterator	Medium
179	Largest Number	Medium
186	Reverse Words in a String II	Medium
187	Repeated DNA Sequences	Medium
189	Rotate Array	Medium
198	House Robber	Medium
199	Binary Tree Right Side View	Medium
200	Number of Islands	Medium
201	Bitwise AND of Numbers Range	Medium
204	Count Primes	Medium
207	Course Schedule	Medium
208	Implement Trie (Prefix Tree)	Medium
209	Minimum Size Subarray Sum	Medium
210	Course Schedule II	Medium
211	Design Add and Search Words Data Structure	Medium
213	House Robber II	Medium
215	Kth Largest Element in an Array	Medium
216	Combination Sum III	Medium
220	Contains Duplicate III	Medium
221	Maximal Square	Medium
222	Count Complete Tree Nodes	Medium
223	Rectangle Area	Medium
227	Basic Calculator II	Medium
229	Majority Element II	Medium
230	Kth Smallest Element in a BST	Medium
236	Lowest Common Ancestor of a Binary Tree	Medium
238	Product of Array Except Self	Medium
240	Search a 2D Matrix II	Medium
241	Different Ways to Add Parentheses	Medium
244	Shortest Word Distance II	Medium
245	Shortest Word Distance III	Medium
247	Strobogrammatic Number II	Medium
249	Group Shifted Strings	Medium
250	Count Univalue Subtrees	Medium
251	Flatten 2D Vector	Medium
253	Meeting Rooms II	Medium
254	Factor Combinations	Medium
255	Verify Preorder Sequence in Binary Search Tree	Medium
256	Paint House	Medium
259	3Sum Smaller	Medium
260	Single Number III	Medium
261	Graph Valid Tree	Medium
264	Ugly Number II	Medium
267	Palindrome Permutation II	Medium
271	Encode and Decode Strings	Medium
274	H-Index	Medium
275	H-Index II	Medium
276	Paint Fence	Medium
277	Find the Celebrity	Medium
279	Perfect Squares	Medium
280	Wiggle Sort	Medium
281	Zigzag Iterator	Medium
284	Peeking Iterator	Medium
285	Inorder Successor in BST	Medium
286	Walls and Gates	Medium
287	Find the Duplicate Number	Medium
288	Unique Word Abbreviation	Medium
289	Game of Life	Medium
291	Word Pattern II	Medium
294	Flip Game II	Medium
298	Binary Tree Longest Consecutive Sequence	Medium
299	Bulls and Cows	Medium
300	Longest Increasing Subsequence	Medium
304	Range Sum Query 2D - Immutable	Medium
306	Additive Number	Medium
307	Range Sum Query - Mutable	Medium
309	Best Time to Buy and Sell Stock with Cooldown	Medium
310	Minimum Height Trees	Medium
311	Sparse Matrix Multiplication	Medium
313	Super Ugly Number	Medium
314	Binary Tree Vertical Order Traversal	Medium
316	Remove Duplicate Letters	Medium
318	Maximum Product of Word Lengths	Medium
319	Bulb Switcher	Medium
320	Generalized Abbreviation	Medium
322	Coin Change	Medium
323	Number of Connected Components in an Undirected Graph	Medium
324	Wiggle Sort II	Medium
325	Maximum Size Subarray Sum Equals k	Medium
328	Odd Even Linked List	Medium
331	Verify Preorder Serialization of a Binary Tree	Medium
333	Largest BST Subtree	Medium
334	Increasing Triplet Subsequence	Medium
337	House Robber III	Medium
339	Nested List Weight Sum	Medium
340	Longest Substring with At Most K Distinct Characters	Medium
341	Flatten Nested List Iterator	Medium
343	Integer Break	Medium
347	Top K Frequent Elements	Medium
348	Design Tic-Tac-Toe	Medium
351	Android Unlock Patterns	Medium
353	Design Snake Game	Medium
355	Design Twitter	Medium
356	Line Reflection	Medium
357	Count Numbers with Unique Digits	Medium
360	Sort Transformed Array	Medium
361	Bomb Enemy	Medium
362	Design Hit Counter	Medium
364	Nested List Weight Sum II	Medium
365	Water and Jug Problem	Medium
366	Find Leaves of Binary Tree	Medium
368	Largest Divisible Subset	Medium
369	Plus One Linked List	Medium
370	Range Addition	Medium
371	Sum of Two Integers	Medium
372	Super Pow	Medium
373	Find K Pairs with Smallest Sums	Medium
375	Guess Number Higher or Lower II	Medium
376	Wiggle Subsequence	Medium
377	Combination Sum IV	Medium
378	Kth Smallest Element in a Sorted Matrix	Medium
379	Design Phone Directory	Medium
380	Insert Delete GetRandom O(1)	Medium
382	Linked List Random Node	Medium
384	Shuffle an Array	Medium
385	Mini Parser	Medium
386	Lexicographical Numbers	Medium
388	Longest Absolute File Path	Medium
390	Elimination Game	Medium
393	UTF-8 Validation	Medium
394	Decode String	Medium
395	Longest Substring with At Least K Repeating Characters	Medium
396	Rotate Function	Medium
397	Integer Replacement	Medium
398	Random Pick Index	Medium
399	Evaluate Division	Medium
400	Nth Digit	Medium
402	Remove K Digits	Medium
406	Queue Reconstruction by Height	Medium
413	Arithmetic Slices	Medium
416	Partition Equal Subset Sum	Medium
417	Pacific Atlantic Water Flow	Medium
418	Sentence Screen Fitting	Medium
419	Battleships in a Board	Medium
421	Maximum XOR of Two Numbers in an Array	Medium
423	Reconstruct Original Digits from English	Medium
424	Longest Repeating Character Replacement	Medium
426	Convert Binary Search Tree to Sorted Doubly Linked List	Medium
427	Construct Quad Tree	Medium
429	N-ary Tree Level Order Traversal	Medium
430	Flatten a Multilevel Doubly Linked List	Medium
433	Minimum Genetic Mutation	Medium
435	Non-overlapping Intervals	Medium
436	Find Right Interval	Medium
437	Path Sum III	Medium
438	Find All Anagrams in a String	Medium
439	Ternary Expression Parser	Medium
442	Find All Duplicates in an Array	Medium
443	String Compression	Medium
444	Sequence Reconstruction	Medium
445	Add Two Numbers II	Medium
447	Number of Boomerangs	Medium
449	Serialize and Deserialize BST	Medium
450	Delete Node in a BST	Medium
451	Sort Characters By Frequency	Medium
452	Minimum Number of Arrows to Burst Balloons	Medium
453	Minimum Moves to Equal Array Elements	Medium
454	4Sum II	Medium
456	132 Pattern	Medium
457	Circular Array Loop	Medium
462	Minimum Moves to Equal Array Elements II	Medium
464	Can I Win	Medium
467	Unique Substrings in Wraparound String	Medium
468	Validate IP Address	Medium
469	Convex Polygon	Medium
470	Implement Rand10() Using Rand7()	Medium
473	Matchsticks to Square	Medium
474	Ones and Zeroes	Medium
475	Heaters	Medium
477	Total Hamming Distance	Medium
478	Generate Random Point in a Circle	Medium
481	Magical String	Medium
484	Find Permutation	Medium
486	Predict the Winner	Medium
487	Max Consecutive Ones II	Medium
490	The Maze	Medium
491	Increasing Subsequences	Medium
494	Target Sum	Medium
497	Random Point in Non-overlapping Rectangles	Medium
498	Diagonal Traverse	Medium
503	Next Greater Element II	Medium
505	The Maze II	Medium
508	Most Frequent Subtree Sum	Medium
510	Inorder Successor in BST II	Medium
513	Find Bottom Left Tree Value	Medium
515	Find Largest Value in Each Tree Row	Medium
516	Longest Palindromic Subsequence	Medium
518	Coin Change 2	Medium
519	Random Flip Matrix	Medium
522	Longest Uncommon Subsequence II	Medium
523	Continuous Subarray Sum	Medium
524	Longest Word in Dictionary through Deleting	Medium
525	Contiguous Array	Medium
526	Beautiful Arrangement	Medium
528	Random Pick with Weight	Medium
529	Minesweeper	Medium
531	Lonely Pixel I	Medium
532	K-diff Pairs in an Array	Medium
533	Lonely Pixel II	Medium
535	Encode and Decode TinyURL	Medium
536	Construct Binary Tree from String	Medium
537	Complex Number Multiplication	Medium
538	Convert BST to Greater Tree	Medium
539	Minimum Time Difference	Medium
540	Single Element in a Sorted Array	Medium
542	01 Matrix	Medium
544	Output Contest Matches	Medium
545	Boundary of Binary Tree	Medium
547	Number of Provinces	Medium
549	Binary Tree Longest Consecutive Sequence II	Medium
553	Optimal Division	Medium
554	Brick Wall	Medium
555	Split Concatenated Strings	Medium
556	Next Greater Element III	Medium
558	Logical OR of Two Binary Grids Represented as Quad-Trees	Medium
560	Subarray Sum Equals K	Medium
562	Longest Line of Consecutive One in Matrix	Medium
565	Array Nesting	Medium
567	Permutation in String	Medium
573	Squirrel Simulation	Medium
576	Out of Boundary Paths	Medium
581	Shortest Unsorted Continuous Subarray	Medium
582	Kill Process	Medium
583	Delete Operation for Two Strings	Medium
592	Fraction Addition and Subtraction	Medium
593	Valid Square	Medium
609	Find Duplicate File in System	Medium
611	Valid Triangle Number	Medium
616	Add Bold Tag in String	Medium
621	Task Scheduler	Medium
622	Design Circular Queue	Medium
623	Add One Row to Tree	Medium
624	Maximum Distance in Arrays	Medium
625	Minimum Factorization	Medium
633	Sum of Square Numbers	Medium
634	Find the Derangement of An Array	Medium
635	Design Log Storage System	Medium
636	Exclusive Time of Functions	Medium
638	Shopping Offers	Medium
640	Solve the Equation	Medium
641	Design Circular Deque	Medium
646	Maximum Length of Pair Chain	Medium
647	Palindromic Substrings	Medium
648	Replace Words	Medium
649	Dota2 Senate	Medium
650	2 Keys Keyboard	Medium
651	4 Keys Keyboard	Medium
652	Find Duplicate Subtrees	Medium
654	Maximum Binary Tree	Medium
655	Print Binary Tree	Medium
658	Find K Closest Elements	Medium
659	Split Array into Consecutive Subsequences	Medium
662	Maximum Width of Binary Tree	Medium
663	Equal Tree Partition	Medium
665	Non-decreasing Array	Medium
666	Path Sum IV	Medium
667	Beautiful Arrangement II	Medium
669	Trim a Binary Search Tree	Medium
670	Maximum Swap	Medium
672	Bulb Switcher II	Medium
673	Number of Longest Increasing Subsequence	Medium
676	Implement Magic Dictionary	Medium
677	Map Sum Pairs	Medium
678	Valid Parenthesis String	Medium
681	Next Closest Time	Medium
684	Redundant Connection	Medium
686	Repeated String Match	Medium
687	Longest Univalue Path	Medium
688	Knight Probability in Chessboard	Medium
690	Employee Importance	Medium
692	Top K Frequent Words	Medium
694	Number of Distinct Islands	Medium
695	Max Area of Island	Medium
698	Partition to K Equal Sum Subsets	Medium
701	Insert into a Binary Search Tree	Medium
702	Search in a Sorted Array of Unknown Size	Medium
707	Design Linked List	Medium
708	Insert into a Sorted Circular Linked List	Medium
712	Minimum ASCII Delete Sum for Two Strings	Medium
713	Subarray Product Less Than K	Medium
714	Best Time to Buy and Sell Stock with Transaction Fee	Medium
718	Maximum Length of Repeated Subarray	Medium
720	Longest Word in Dictionary	Medium
721	Accounts Merge	Medium
722	Remove Comments	Medium
723	Candy Crush	Medium
725	Split Linked List in Parts	Medium
729	My Calendar I	Medium
731	My Calendar II	Medium
735	Asteroid Collision	Medium
737	Sentence Similarity II	Medium
738	Monotone Increasing Digits	Medium
739	Daily Temperatures	Medium
740	Delete and Earn	Medium
742	Closest Leaf in a Binary Tree	Medium
743	Network Delay Time	Medium
750	Number Of Corner Rectangles	Medium
751	IP to CIDR	Medium
752	Open the Lock	Medium
754	Reach a Number	Medium
755	Pour Water	Medium
756	Pyramid Transition Matrix	Medium
758	Bold Words in String	Medium
763	Partition Labels	Medium
764	Largest Plus Sign	Medium
767	Reorganize String	Medium
769	Max Chunks To Make Sorted	Medium
775	Global and Local Inversions	Medium
776	Split BST	Medium
777	Swap Adjacent in LR String	Medium
779	K-th Symbol in Grammar	Medium
781	Rabbits in Forest	Medium
784	Letter Case Permutation	Medium
785	Is Graph Bipartite?	Medium
787	Cheapest Flights Within K Stops	Medium
788	Rotated Digits	Medium
789	Escape The Ghosts	Medium
790	Domino and Tromino Tiling	Medium
791	Custom Sort String	Medium
792	Number of Matching Subsequences	Medium
794	Valid Tic-Tac-Toe State	Medium
795	Number of Subarrays with Bounded Maximum	Medium
797	All Paths From Source to Target	Medium
799	Champagne Tower	Medium
802	Find Eventual Safe States	Medium
807	Max Increase to Keep City Skyline	Medium
808	Soup Servings	Medium
809	Expressive Words	Medium
811	Subdomain Visit Count	Medium
813	Largest Sum of Averages	Medium
814	Binary Tree Pruning	Medium
816	Ambiguous Coordinates	Medium
817	Linked List Components	Medium
820	Short Encoding of Words	Medium
822	Card Flipping Game	Medium
823	Binary Trees With Factors	Medium
825	Friends Of Appropriate Ages	Medium
826	Most Profit Assigning Work	Medium
831	Masking Personal Information	Medium
833	Find And Replace in String	Medium
835	Image Overlap	Medium
837	New 21 Game	Medium
838	Push Dominoes	Medium
840	Magic Squares In Grid	Medium
841	Keys and Rooms	Medium
842	Split Array into Fibonacci Sequence	Medium
845	Longest Mountain in Array	Medium
846	Hand of Straights	Medium
848	Shifting Letters	Medium
849	Maximize Distance to Closest Person	Medium
851	Loud and Rich	Medium
853	Car Fleet	Medium
855	Exam Room	Medium
856	Score of Parentheses	Medium
858	Mirror Reflection	Medium
861	Score After Flipping Matrix	Medium
863	All Nodes Distance K in Binary Tree	Medium
865	Smallest Subtree with all the Deepest Nodes	Medium
866	Prime Palindrome	Medium
869	Reordered Power of 2	Medium
870	Advantage Shuffle	Medium
873	Length of Longest Fibonacci Subsequence	Medium
874	Walking Robot Simulation	Medium
875	Koko Eating Bananas	Medium
877	Stone Game	Medium
880	Decoded String at Index	Medium
881	Boats to Save People	Medium
885	Spiral Matrix III	Medium
886	Possible Bipartition	Medium
889	Construct Binary Tree from Preorder and Postorder Traversal	Medium
890	Find and Replace Pattern	Medium
893	Groups of Special-Equivalent Strings	Medium
894	All Possible Full Binary Trees	Medium
898	Bitwise ORs of Subarrays	Medium
900	RLE Iterator	Medium
901	Online Stock Span	Medium
904	Fruit Into Baskets	Medium
907	Sum of Subarray Minimums	Medium
909	Snakes and Ladders	Medium
910	Smallest Range II	Medium
911	Online Election	Medium
912	Sort an Array	Medium
915	Partition Array into Disjoint Intervals	Medium
916	Word Subsets	Medium
918	Maximum Sum Circular Subarray	Medium
919	Complete Binary Tree Inserter	Medium
921	Minimum Add to Make Parentheses Valid	Medium
923	3Sum With Multiplicity	Medium
926	Flip String to Monotone Increasing	Medium
930	Binary Subarrays With Sum	Medium
931	Minimum Falling Path Sum	Medium
932	Beautiful Array	Medium
934	Shortest Bridge	Medium
935	Knight Dialer	Medium
939	Minimum Area Rectangle	Medium
945	Minimum Increment to Make Array Unique	Medium
946	Validate Stack Sequences	Medium
947	Most Stones Removed with Same Row or Column	Medium
948	Bag of Tokens	Medium
949	Largest Time for Given Digits	Medium
950	Reveal Cards In Increasing Order	Medium
951	Flip Equivalent Binary Trees	Medium
954	Array of Doubled Pairs	Medium
955	Delete Columns to Make Sorted II	Medium
957	Prison Cells After N Days	Medium
958	Check Completeness of a Binary Tree	Medium
959	Regions Cut By Slashes	Medium
962	Maximum Width Ramp	Medium
963	Minimum Area Rectangle II	Medium
966	Vowel Spellchecker	Medium
967	Numbers With Same Consecutive Differences	Medium
969	Pancake Sorting	Medium
970	Powerful Integers	Medium
971	Flip Binary Tree To Match Preorder Traversal	Medium
973	K Closest Points to Origin	Medium
974	Subarray Sums Divisible by K	Medium
978	Longest Turbulent Subarray	Medium
979	Distribute Coins in Binary Tree	Medium
981	Time Based Key-Value Store	Medium
983	Minimum Cost For Tickets	Medium
984	String Without AAA or BBB	Medium
985	Sum of Even Numbers After Queries	Medium
986	Interval List Intersections	Medium
988	Smallest String Starting From Leaf	Medium
990	Satisfiability of Equality Equations	Medium
991	Broken Calculator	Medium
994	Rotting Oranges	Medium
998	Maximum Binary Tree II	Medium
1003	Check If Word Is Valid After Substitutions	Medium
1004	Max Consecutive Ones III	Medium
1006	Clumsy Factorial	Medium
1007	Minimum Domino Rotations For Equal Row	Medium
1008	Construct Binary Search Tree from Preorder Traversal	Medium
1010	Pairs of Songs With Total Durations Divisible by 60	Medium
1011	Capacity To Ship Packages Within D Days	Medium
1014	Best Sightseeing Pair	Medium
1015	Smallest Integer Divisible by K	Medium
1016	Binary String With Substrings Representing 1 To N	Medium
1017	Convert to Base -2	Medium
1019	Next Greater Node In Linked List	Medium
1020	Number of Enclaves	Medium
1023	Camelcase Matching	Medium
1024	Video Stitching	Medium
1026	Maximum Difference Between Node and Ancestor	Medium
1027	Longest Arithmetic Subsequence	Medium
1029	Two City Scheduling	Medium
1031	Maximum Sum of Two Non-Overlapping Subarrays	Medium
1033	Moving Stones Until Consecutive	Medium
1034	Coloring A Border	Medium
1035	Uncrossed Lines	Medium
1038	Binary Search Tree to Greater Sum Tree	Medium
1039	Minimum Score Triangulation of Polygon	Medium
1040	Moving Stones Until Consecutive II	Medium
1041	Robot Bounded In Circle	Medium
1042	Flower Planting With No Adjacent	Medium
1043	Partition Array for Maximum Sum	Medium
1048	Longest String Chain	Medium
1049	Last Stone Weight II	Medium
1052	Grumpy Bookstore Owner	Medium
1053	Previous Permutation With One Swap	Medium
1054	Distant Barcodes	Medium
1055	Shortest Way to Form String	Medium
1057	Campus Bikes	Medium
1058	Minimize Rounding Error to Meet Target	Medium
1059	All Paths from Source Lead to Destination	Medium
1060	Missing Element in Sorted Array	Medium
1061	Lexicographically Smallest Equivalent String	Medium
1062	Longest Repeating Substring	Medium
1066	Campus Bikes II	Medium
1072	Flip Columns For Maximum Number of Equal Rows	Medium
1073	Adding Two Negabinary Numbers	Medium
1079	Letter Tile Possibilities	Medium
1080	Insufficient Nodes in Root to Leaf Paths	Medium
1081	Smallest Subsequence of Distinct Characters	Medium
1087	Brace Expansion	Medium
1090	Largest Values From Labels	Medium
1091	Shortest Path in Binary Matrix	Medium
1093	Statistics from a Large Sample	Medium
1094	Car Pooling	Medium
1100	Find K-Length Substrings With No Repeated Characters	Medium
1101	The Earliest Moment When Everyone Become Friends	Medium
1102	Path With Maximum Minimum Value	Medium
1104	Path In Zigzag Labelled Binary Tree	Medium
1105	Filling Bookcase Shelves	Medium
1109	Corporate Flight Bookings	Medium
1110	Delete Nodes And Return Forest	Medium
1111	Maximum Nesting Depth of Two Valid Parentheses Strings	Medium
1115	Print FooBar Alternately	Medium
1116	Print Zero Even Odd	Medium
1117	Building H2O	Medium
1120	Maximum Average Subtree	Medium
1123	Lowest Common Ancestor of Deepest Leaves	Medium
1124	Longest Well-Performing Interval	Medium
1129	Shortest Path with Alternating Colors	Medium
1130	Minimum Cost Tree From Leaf Values	Medium
1131	Maximum of Absolute Value Expression	Medium
1135	Connecting Cities With Minimum Cost	Medium
1136	Parallel Courses	Medium
1138	Alphabet Board Path	Medium
1139	Largest 1-Bordered Square	Medium
1140	Stone Game II	Medium
1143	Longest Common Subsequence	Medium
1144	Decrease Elements To Make Array Zigzag	Medium
1145	Binary Tree Coloring Game	Medium
1146	Snapshot Array	Medium
1151	Minimum Swaps to Group All 1's Together	Medium
1152	Analyze User Website Visit Pattern	Medium
1155	Number of Dice Rolls With Target Sum	Medium
1156	Swap For Longest Repeated Character Substring	Medium
1161	Maximum Level Sum of a Binary Tree	Medium
1162	As Far from Land as Possible	Medium
1166	Design File System	Medium
1167	Minimum Cost to Connect Sticks	Medium
1169	Invalid Transactions	Medium
1170	Compare Strings by Frequency of the Smallest Character	Medium
1171	Remove Zero Sum Consecutive Nodes from Linked List	Medium
1177	Can Make Palindrome from Substring	Medium
1181	Before and After Puzzle	Medium
1182	Shortest Distance to Target Color	Medium
1186	Maximum Subarray Sum with One Deletion	Medium
1188	Design Bounded Blocking Queue	Medium
1190	Reverse Substrings Between Each Pair of Parentheses	Medium
1191	K-Concatenation Maximum Sum	Medium
1195	Fizz Buzz Multithreaded	Medium
1197	Minimum Knight Moves	Medium
1198	Find Smallest Common Element in All Rows	Medium
1201	Ugly Number III	Medium
1202	Smallest String With Swaps	Medium
1208	Get Equal Substrings Within Budget	Medium
1209	Remove All Adjacent Duplicates in String II	Medium
1214	Two Sum BSTs	Medium
1215	Stepping Numbers	Medium
1218	Longest Arithmetic Subsequence of Given Difference	Medium
1219	Path with Maximum Gold	Medium
1222	Queens That Can Attack the King	Medium
1226	The Dining Philosophers	Medium
1227	Airplane Seat Assignment Probability	Medium
1229	Meeting Scheduler	Medium
1230	Toss Strange Coins	Medium
1233	Remove Sub-Folders from the Filesystem	Medium
1234	Replace the Substring for Balanced String	Medium
1236	Web Crawler	Medium
1237	Find Positive Integer Solution for a Given Equation	Medium
1238	Circular Permutation in Binary Representation	Medium
1239	Maximum Length of a Concatenated String with Unique Characters	Medium
1242	Web Crawler Multithreaded	Medium
1244	Design A Leaderboard	Medium
1245	Tree Diameter	Medium
1247	Minimum Swaps to Make Strings Equal	Medium
1248	Count Number of Nice Subarrays	Medium
1249	Minimum Remove to Make Valid Parentheses	Medium
1253	Reconstruct a 2-Row Binary Matrix	Medium
1254	Number of Closed Islands	Medium
1256	Encode Number	Medium
1257	Smallest Common Region	Medium
1258	Synonymous Sentences	Medium
1261	Find Elements in a Contaminated Binary Tree	Medium
1262	Greatest Sum Divisible by Three	Medium
1265	Print Immutable Linked List in Reverse	Medium
1267	Count Servers that Communicate	Medium
1268	Search Suggestions System	Medium
1272	Remove Interval	Medium
1273	Delete Tree Nodes	Medium
1276	Number of Burgers with No Waste of Ingredients	Medium
1277	Count Square Submatrices with All Ones	Medium
1282	Group the People Given the Group Size They Belong To	Medium
1283	Find the Smallest Divisor Given a Threshold	Medium
1286	Iterator for Combination	Medium
1288	Remove Covered Intervals	Medium
1291	Sequential Digits	Medium
1292	Maximum Side Length of a Square with Sum Less than or Equal to Threshold	Medium
1296	Divide Array in Sets of K Consecutive Numbers	Medium
1297	Maximum Number of Occurrences of a Substring	Medium
1300	Sum of Mutated Array Closest to Target	Medium
1302	Deepest Leaves Sum	Medium
1305	All Elements in Two Binary Search Trees	Medium
1306	Jump Game III	Medium
1310	XOR Queries of a Subarray	Medium
1311	Get Watched Videos by Your Friends	Medium
1314	Matrix Block Sum	Medium
1315	Sum of Nodes with Even-Valued Grandparent	Medium
1318	Minimum Flips to Make a OR b Equal to c	Medium
1319	Number of Operations to Make Network Connected	Medium
1324	Print Words Vertically	Medium
1325	Delete Leaves With a Given Value	Medium
1328	Break a Palindrome	Medium
1329	Sort the Matrix Diagonally	Medium
1333	Filter Restaurants by Vegan-Friendly, Price and Distance	Medium
1334	Find the City With the Smallest Number of Neighbors at a Threshold Distance	Medium
1338	Reduce Array Size to The Half	Medium
1339	Maximum Product of Splitted Binary Tree	Medium
1343	Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold	Medium
1344	Angle Between Hands of a Clock	Medium
1347	Minimum Number of Steps to Make Two Strings Anagram	Medium
1348	Tweet Counts Per Frequency	Medium
1352	Product of the Last K Numbers	Medium
1353	Maximum Number of Events That Can Be Attended	Medium
1357	Apply Discount Every n Orders	Medium
1358	Number of Substrings Containing All Three Characters	Medium
1361	Validate Binary Tree Nodes	Medium
1362	Closest Divisors	Medium
1366	Rank Teams by Votes	Medium
1367	Linked List in Binary Tree	Medium
1371	Find the Longest Substring Containing Vowels in Even Counts	Medium
1372	Longest ZigZag Path in a Binary Tree	Medium
1375	Number of Times Binary String Is Prefix-Aligned	Medium
1376	Time Needed to Inform All Employees	Medium
1379	Find a Corresponding Node of a Binary Tree in a Clone of That Tree	Medium
1381	Design a Stack With Increment Operation	Medium
1382	Balance a Binary Search Tree	Medium
1386	Cinema Seat Allocation	Medium
1387	Sort Integers by The Power Value	Medium
1390	Four Divisors	Medium
1391	Check if There is a Valid Path in a Grid	Medium
1395	Count Number of Teams	Medium
1396	Design Underground System	Medium
1400	Construct K Palindrome Strings	Medium
1401	Circle and Rectangle Overlapping	Medium
1404	Number of Steps to Reduce a Number in Binary Representation to One	Medium
1405	Longest Happy String	Medium
1409	Queries on a Permutation With Key	Medium
1410	HTML Entity Parser	Medium
1414	Find the Minimum Number of Fibonacci Numbers Whose Sum Is K	Medium
1415	The k-th Lexicographical String of All Happy Strings of Length n	Medium
1418	Display Table of Food Orders in a Restaurant	Medium
1419	Minimum Number of Frogs Croaking	Medium
1423	Maximum Points You Can Obtain from Cards	Medium
1424	Diagonal Traverse II	Medium
1428	Leftmost Column with at Least a One	Medium
1429	First Unique Number	Medium
1430	Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree	Medium
1432	Max Difference You Can Get From Changing an Integer	Medium
1433	Check If a String Can Break Another String	Medium
1438	Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit	Medium
1442	Count Triplets That Can Form Two Arrays of Equal XOR	Medium
1443	Minimum Time to Collect All Apples in a Tree	Medium
1447	Simplified Fractions	Medium
1448	Count Good Nodes in Binary Tree	Medium
1451	Rearrange Words in a Sentence	Medium
1452	People Whose List of Favorite Companies Is Not a Subset of Another List	Medium
1456	Maximum Number of Vowels in a Substring of Given Length	Medium
1457	Pseudo-Palindromic Paths in a Binary Tree	Medium
1461	Check If a String Contains All Binary Codes of Size K	Medium
1462	Course Schedule IV	Medium
1465	Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts	Medium
1466	Reorder Routes to Make All Paths Lead to the City Zero	Medium
1471	The k Strongest Values in an Array	Medium
1472	Design Browser History	Medium
1476	Subrectangle Queries	Medium
1477	Find Two Non-overlapping Sub-arrays Each With Target Sum	Medium
1481	Least Number of Unique Integers after K Removals	Medium
1482	Minimum Number of Days to Make m Bouquets	Medium
1485	Clone Binary Tree With Random Pointer	Medium
1487	Making File Names Unique	Medium
1488	Avoid Flood in The City	Medium
1490	Clone N-ary Tree	Medium
1492	The kth Factor of n	Medium
1493	Longest Subarray of 1's After Deleting One Element	Medium
1497	Check If Array Pairs Are Divisible by k	Medium
1498	Number of Subsequences That Satisfy the Given Sum Condition	Medium
1500	Design a File Sharing System	Medium
1503	Last Moment Before All Ants Fall Out of a Plank	Medium
1504	Count Submatrices With All Ones	Medium
1506	Find Root of N-Ary Tree	Medium
1508	Range Sum of Sorted Subarray Sums	Medium
1509	Minimum Difference Between Largest and Smallest Value in Three Moves	Medium
1513	Number of Substrings With Only 1s	Medium
1514	Path with Maximum Probability	Medium
1519	Number of Nodes in the Sub-Tree With the Same Label	Medium
1522	Diameter of N-Ary Tree	Medium
1524	Number of Sub-arrays With Odd Sum	Medium
1525	Number of Good Ways to Split a String	Medium
1529	Minimum Suffix Flips	Medium
1530	Number of Good Leaf Nodes Pairs	Medium
1533	Find the Index of the Large Integer	Medium
1535	Find the Winner of an Array Game	Medium
1536	Minimum Swaps to Arrange a Binary Grid	Medium
1538	Guess the Majority in a Hidden Array	Medium
1540	Can Convert String in K Moves	Medium
1541	Minimum Insertions to Balance a Parentheses String	Medium
1545	Find Kth Bit in Nth Binary String	Medium
1546	Maximum Number of Non-Overlapping Subarrays With Sum Equals Target	Medium
1551	Minimum Operations to Make Array Equal	Medium
1552	Magnetic Force Between Two Balls	Medium
1554	Strings Differ by One Character	Medium
1557	Minimum Number of Vertices to Reach All Nodes	Medium
1558	Minimum Numbers of Function Calls to Make Target Array	Medium
1559	Detect Cycles in 2D Grid	Medium
1561	Maximum Number of Coins You Can Get	Medium
1562	Find Latest Group of Size M	Medium
1564	Put Boxes Into the Warehouse I	Medium
1567	Maximum Length of Subarray With Positive Product	Medium
1570	Dot Product of Two Sparse Vectors	Medium
1573	Number of Ways to Split a String	Medium
1574	Shortest Subarray to be Removed to Make Array Sorted	Medium
1577	Number of Ways Where Square of Number Is Equal to Product of Two Numbers	Medium
1578	Minimum Time to Make Rope Colorful	Medium
1580	Put Boxes Into the Warehouse II	Medium
1583	Count Unhappy Friends	Medium
1584	Min Cost to Connect All Points	Medium
1586	Binary Search Tree Iterator II	Medium
1589	Maximum Sum Obtained of Any Permutation	Medium
1590	Make Sum Divisible by P	Medium
1593	Split a String Into the Max Number of Unique Substrings	Medium
1594	Maximum Non Negative Product in a Matrix	Medium
1599	Maximum Profit of Operating a Centennial Wheel	Medium
1600	Throne Inheritance	Medium
1602	Find Nearest Right Node in Binary Tree	Medium
1604	Alert Using Same Key-Card Three or More Times in a One Hour Period	Medium
1605	Find Valid Matrix Given Row and Column Sums	Medium
1609	Even Odd Tree	Medium
1612	Check If Two Expression Trees are Equivalent	Medium
1615	Maximal Network Rank	Medium
1616	Split Two Strings to Make Palindrome	Medium
1618	Maximum Font to Fit a Sentence in a Screen	Medium
1620	Coordinate With Maximum Network Quality	Medium
1621	Number of Sets of K Non-Overlapping Line Segments	Medium
1625	Lexicographically Smallest String After Applying Operations	Medium
1626	Best Team With No Conflicts	Medium
1628	Design an Expression Tree With Evaluate Function	Medium
1630	Arithmetic Subarrays	Medium
1631	Path With Minimum Effort	Medium
1634	Add Two Polynomials Represented as Linked Lists	Medium
1637	Widest Vertical Area Between Two Points Containing No Points	Medium
1638	Count Substrings That Differ by One Character	Medium
1641	Count Sorted Vowel Strings	Medium
1642	Furthest Building You Can Reach	Medium
1644	Lowest Common Ancestor of a Binary Tree II	Medium
1647	Minimum Deletions to Make Character Frequencies Unique	Medium
1648	Sell Diminishing-Valued Colored Balls	Medium
1650	Lowest Common Ancestor of a Binary Tree III	Medium
1653	Minimum Deletions to Make String Balanced	Medium
1654	Minimum Jumps to Reach Home	Medium
1657	Determine if Two Strings Are Close	Medium
1658	Minimum Operations to Reduce X to Zero	Medium
1660	Correct a Binary Tree	Medium
1663	Smallest String With A Given Numeric Value	Medium
1664	Ways to Make a Fair Array	Medium
1666	Change the Root of a Binary Tree	Medium
1669	Merge In Between Linked Lists	Medium
1670	Design Front Middle Back Queue	Medium
1673	Find the Most Competitive Subsequence	Medium
1674	Minimum Moves to Make Array Complementary	Medium
1676	Lowest Common Ancestor of a Binary Tree IV	Medium
1679	Max Number of K-Sum Pairs	Medium
1680	Concatenation of Consecutive Binary Numbers	Medium
1682	Longest Palindromic Subsequence II	Medium
1685	Sum of Absolute Differences in a Sorted Array	Medium
1686	Stone Game VI	Medium
1689	Partitioning Into Minimum Number Of Deci-Binary Numbers	Medium
1690	Stone Game VII	Medium
1695	Maximum Erasure Value	Medium
1696	Jump Game VI	Medium
1698	Number of Distinct Substrings in a String	Medium
1701	Average Waiting Time	Medium
1702	Maximum Binary String After Change	Medium
1705	Maximum Number of Eaten Apples	Medium
1706	Where Will the Ball Fall	Medium
1711	Count Good Meals	Medium
1712	Ways to Split Array Into Three Subarrays	Medium
1717	Maximum Score From Removing Substrings	Medium
1718	Construct the Lexicographically Largest Valid Sequence	Medium
1721	Swapping Nodes in a Linked List	Medium
1722	Minimize Hamming Distance After Swap Operations	Medium
1726	Tuple with Same Product	Medium
1727	Largest Submatrix With Rearrangements	Medium
1730	Shortest Path to Get Food	Medium
1733	Minimum Number of People to Teach	Medium
1734	Decode XORed Permutation	Medium
1737	Change Minimum Characters to Satisfy One of Three Conditions	Medium
1738	Find Kth Largest XOR Coordinate Value	Medium
1740	Find Distance in a Binary Tree	Medium
1743	Restore the Array From Adjacent Pairs	Medium
1744	Can You Eat Your Favorite Candy on Your Favorite Day?	Medium
1746	Maximum Subarray Sum After One Operation	Medium
1749	Maximum Absolute Sum of Any Subarray	Medium
1750	Minimum Length of String After Deleting Similar Ends	Medium
1753	Maximum Score From Removing Stones	Medium
1754	Largest Merge Of Two Strings	Medium
1756	Design Most Recently Used Queue	Medium
1759	Count Number of Homogenous Substrings	Medium
1760	Minimum Limit of Balls in a Bag	Medium
1762	Buildings With an Ocean View	Medium
1764	Form Array by Concatenating Subarrays of Another Array	Medium
1765	Map of Highest Peak	Medium
1769	Minimum Number of Operations to Move All Balls to Each Box	Medium
1770	Maximum Score from Performing Multiplication Operations	Medium
1772	Sort Features by Popularity	Medium
1774	Closest Dessert Cost	Medium
1775	Equal Sum Arrays With Minimum Number of Operations	Medium
1778	Shortest Path in a Hidden Grid	Medium
1780	Check if Number is a Sum of Powers of Three	Medium
1781	Sum of Beauty of All Substrings	Medium
1785	Minimum Elements to Add to Form a Given Sum	Medium
1786	Number of Restricted Paths From First to Last Node	Medium
1792	Maximum Average Pass Ratio	Medium
1794	Count Pairs of Equal Substrings With Minimum Difference	Medium
1797	Design Authentication Manager	Medium
1798	Maximum Number of Consecutive Values You Can Make	Medium
1801	Number of Orders in the Backlog	Medium
1802	Maximum Value at a Given Index in a Bounded Array	Medium
1804	Implement Trie II (Prefix Tree)	Medium
1806	Minimum Number of Operations to Reinitialize a Permutation	Medium
1807	Evaluate the Bracket Pairs of a String	Medium
1810	Minimum Path Cost in a Hidden Grid	Medium
1813	Sentence Similarity III	Medium
1814	Count Nice Pairs in an Array	Medium
1817	Finding the Users Active Minutes	Medium
1818	Minimum Absolute Sum Difference	Medium
1820	Maximum Number of Accepted Invitations	Medium
1823	Find the Winner of the Circular Game	Medium
1824	Minimum Sideway Jumps	Medium
1828	Queries on Number of Points Inside a Circle	Medium
1829	Maximum XOR for Each Query	Medium
1833	Maximum Ice Cream Bars	Medium
1834	Single-Threaded CPU	Medium
1836	Remove Duplicates From an Unsorted Linked List	Medium
1838	Frequency of the Most Frequent Element	Medium
1839	Longest Substring Of All Vowels in Order	Medium
1845	Seat Reservation Manager	Medium
1846	Maximum Element After Decreasing and Rearranging	Medium
1849	Splitting a String Into Descending Consecutive Values	Medium
1850	Minimum Adjacent Swaps to Reach the Kth Smallest Number	Medium
1852	Distinct Numbers in Each Subarray	Medium
1855	Maximum Distance Between a Pair of Values	Medium
1856	Maximum Subarray Min-Product	Medium
1858	Longest Word With All Prefixes	Medium
1860	Incremental Memory Leak	Medium
1861	Rotating the Box	Medium
1864	Minimum Number of Swaps to Make the Binary String Alternating	Medium
1865	Finding Pairs With a Certain Sum	Medium
1868	Product of Two Run-Length Encoded Arrays	Medium
1870	Minimum Speed to Arrive on Time	Medium
1871	Jump Game VII	Medium
1874	Minimize Product Sum of Two Arrays	Medium
1877	Minimize Maximum Pair Sum in Array	Medium
1878	Get Biggest Three Rhombus Sums in a Grid	Medium
1881	Maximum Value after Insertion	Medium
1882	Process Tasks Using Servers	Medium
1884	Egg Drop With 2 Eggs and N Floors	Medium
1885	Count Pairs in Two Arrays	Medium
1887	Reduction Operations to Make the Array Elements Equal	Medium
1888	Minimum Number of Flips to Make the Binary String Alternating	Medium
1891	Cutting Ribbons	Medium
1894	Find the Student that Will Replace the Chalk	Medium
1895	Largest Magic Square	Medium
1898	Maximum Number of Removable Characters	Medium
1899	Merge Triplets to Form Target Triplet	Medium
1901	Find a Peak Element II	Medium
1902	Depth of BST Given Insertion Order	Medium
1904	The Number of Full Rounds You Have Played	Medium
1905	Count Sub Islands	Medium
1906	Minimum Absolute Difference Queries	Medium
1908	Game of Nim	Medium
1910	Remove All Occurrences of a Substring	Medium
1911	Maximum Alternating Subsequence Sum	Medium
1914	Cyclically Rotating a Grid	Medium
1915	Number of Wonderful Substrings	Medium
1918	Kth Smallest Subarray Sum	Medium
1921	Eliminate Maximum Number of Monsters	Medium
1922	Count Good Numbers	Medium
1926	Nearest Exit from Entrance in Maze	Medium
1927	Sum Game	Medium
1930	Unique Length-3 Palindromic Subsequences	Medium
1936	Add Minimum Number of Rungs	Medium
1937	Maximum Number of Points with Cost	Medium
1940	Longest Common Subsequence Between Sorted Arrays	Medium
1942	The Number of the Smallest Unoccupied Chair	Medium
1943	Describe the Painting	Medium
1946	Largest Number After Mutating Substring	Medium
1947	Maximum Compatibility Score Sum	Medium
1950	Maximum of Minimum Values in All Subarrays	Medium
1953	Maximum Number of Weeks for Which You Can Work	Medium
1954	Minimum Garden Perimeter to Collect Enough Apples	Medium
1958	Check if Move is Legal	Medium
1959	Minimum Total Space Wasted With K Resizing Operations	Medium
1962	Remove Stones to Minimize the Total	Medium
1963	Minimum Number of Swaps to Make the String Balanced	Medium
1966	Binary Searchable Numbers in an Unsorted Array	Medium
1968	Array With Elements Not Equal to Average of Neighbors	Medium
1969	Minimum Non-Zero Product of the Array Elements	Medium
1973	Count Nodes Equal to Sum of Descendants	Medium
1975	Maximum Matrix Sum	Medium
1976	Number of Ways to Arrive at Destination	Medium
1980	Find Unique Binary String	Medium
1981	Minimize the Difference Between Target and Chosen Elements	Medium
1983	Widest Pair of Indices With Equal Range Sum	Medium
1985	Find the Kth Largest Integer in the Array	Medium
1986	Minimum Number of Work Sessions to Finish the Tasks	Medium
1989	Maximum Number of People That Can Be Caught in Tag	Medium
1992	Find All Groups of Farmland	Medium
1993	Operations on Tree	Medium
1996	The Number of Weak Characters in the Game	Medium
1997	First Day Where You Have Been in All the Rooms	Medium
1999	Smallest Greater Multiple Made of Two Digits	Medium
2001	Number of Pairs of Interchangeable Rectangles	Medium
2002	Maximum Product of the Length of Two Palindromic Subsequences	Medium
2007	Find Original Array From Doubled Array	Medium
2008	Maximum Earnings From Taxi	Medium
2012	Sum of Beauty in the Array	Medium
2013	Detect Squares	Medium
2015	Average Height of Buildings in Each Segment	Medium
2017	Grid Game	Medium
2018	Check if Word Can Be Placed In Crossword	Medium
2021	Brightest Position on Street	Medium
2023	Number of Pairs of Strings With Concatenation Equal to Target	Medium
2024	Maximize the Confusion of an Exam	Medium
2028	Find Missing Observations	Medium
2029	Stone Game IX	Medium
2031	Count Subarrays With More Ones Than Zeros	Medium
2033	Minimum Operations to Make a Uni-Value Grid	Medium
2034	Stock Price Fluctuation	Medium
2036	Maximum Alternating Subarray Sum	Medium
2038	Remove Colored Pieces if Both Neighbors are the Same Color	Medium
2039	The Time When the Network Becomes Idle	Medium
2043	Simple Bank System	Medium
2044	Count Number of Maximum Bitwise-OR Subsets	Medium
2046	Sort Linked List Already Sorted Using Absolute Values	Medium
2048	Next Greater Numerically Balanced Number	Medium
2049	Count Nodes With the Highest Score	Medium
2052	Minimum Cost to Separate Sentence Into Rows	Medium
2054	Two Best Non-Overlapping Events	Medium
2055	Plates Between Candles	Medium
2058	Find the Minimum and Maximum Number of Nodes Between Critical Points	Medium
2059	Minimum Operations to Convert Number	Medium
2061	Number of Spaces Cleaning Robot Cleaned	Medium
2063	Vowels of All Substrings	Medium
2064	Minimized Maximum of Products Distributed to Any Store	Medium
2067	Number of Equal Count Substrings	Medium
2069	Walking Robot Simulation II	Medium
2070	Most Beautiful Item for Each Query	Medium
2074	Reverse Nodes in Even Length Groups	Medium
2075	Decode the Slanted Ciphertext	Medium
2077	Paths in Maze That Lead to Same Room	Medium
2079	Watering Plants	Medium
2080	Range Frequency Queries	Medium
2083	Substrings That Begin and End With the Same Letter	Medium
2086	Minimum Number of Buckets Required to Collect Rainwater from Houses	Medium
2087	Minimum Cost Homecoming of a Robot in a Grid	Medium
2090	K Radius Subarray Averages	Medium
2091	Removing Minimum and Maximum From Array	Medium
2093	Minimum Cost to Reach City With Discounts	Medium
2095	Delete the Middle Node of a Linked List	Medium
2096	Step-By-Step Directions From a Binary Tree Node to Another	Medium
2098	Subsequence of Size K With the Largest Even Sum	Medium
2100	Find Good Days to Rob the Bank	Medium
2101	Detonate the Maximum Bombs	Medium
2104	Sum of Subarray Ranges	Medium
2105	Watering Plants II	Medium
2107	Number of Unique Flavors After Sharing K Candies	Medium
2109	Adding Spaces to a String	Medium
2110	Number of Smooth Descent Periods of a Stock	Medium
2113	Elements in Array After Removing and Replacing Elements	Medium
2115	Find All Possible Recipes from Given Supplies	Medium
2116	Check if a Parentheses String Can Be Valid	Medium
2120	Execution of All Suffix Instructions Staying in a Grid	Medium
2121	Intervals Between Identical Elements	Medium
2125	Number of Laser Beams in a Bank	Medium
2126	Destroying Asteroids	Medium
2128	Remove All Ones With Row and Column Flips	Medium
2130	Maximum Twin Sum of a Linked List	Medium
2131	Longest Palindrome by Concatenating Two Letter Words	Medium
2134	Minimum Swaps to Group All 1's Together II	Medium
2135	Count Words Obtained After Adding a Letter	Medium
2137	Pour Water Between Buckets to Make Water Levels Equal	Medium
2139	Minimum Moves to Reach Target Score	Medium
2140	Solving Questions With Brainpower	Medium
2145	Count the Hidden Sequences	Medium
2146	K Highest Ranked Items Within a Price Range	Medium
2149	Rearrange Array Elements by Sign	Medium
2150	Find All Lonely Numbers in the Array	Medium
4	Median of Two Sorted Arrays	Hard
10	Regular Expression Matching	Hard
23	Merge k Sorted Lists	Hard
25	Reverse Nodes in k-Group	Hard
30	Substring with Concatenation of All Words	Hard
32	Longest Valid Parentheses	Hard
37	Sudoku Solver	Hard
41	First Missing Positive	Hard
42	Trapping Rain Water	Hard
44	Wildcard Matching	Hard
51	N-Queens	Hard
52	N-Queens II	Hard
60	Permutation Sequence	Hard
65	Valid Number	Hard
68	Text Justification	Hard
72	Edit Distance	Hard
76	Minimum Window Substring	Hard
84	Largest Rectangle in Histogram	Hard
85	Maximal Rectangle	Hard
87	Scramble String	Hard
115	Distinct Subsequences	Hard
123	Best Time to Buy and Sell Stock III	Hard
124	Binary Tree Maximum Path Sum	Hard
126	Word Ladder II	Hard
127	Word Ladder	Hard
132	Palindrome Partitioning II	Hard
135	Candy	Hard
140	Word Break II	Hard
149	Max Points on a Line	Hard
154	Find Minimum in Rotated Sorted Array II	Hard
158	Read N Characters Given read4 II - Call Multiple Times	Hard
164	Maximum Gap	Hard
174	Dungeon Game	Hard
188	Best Time to Buy and Sell Stock IV	Hard
212	Word Search II	Hard
214	Shortest Palindrome	Hard
218	The Skyline Problem	Hard
224	Basic Calculator	Hard
233	Number of Digit One	Hard
239	Sliding Window Maximum	Hard
248	Strobogrammatic Number III	Hard
265	Paint House II	Hard
269	Alien Dictionary	Hard
272	Closest Binary Search Tree Value II	Hard
273	Integer to English Words	Hard
282	Expression Add Operators	Hard
295	Find Median from Data Stream	Hard
296	Best Meeting Point	Hard
297	Serialize and Deserialize Binary Tree	Hard
301	Remove Invalid Parentheses	Hard
302	Smallest Rectangle Enclosing Black Pixels	Hard
305	Number of Islands II	Hard
308	Range Sum Query 2D - Mutable	Hard
312	Burst Balloons	Hard
315	Count of Smaller Numbers After Self	Hard
317	Shortest Distance from All Buildings	Hard
321	Create Maximum Number	Hard
327	Count of Range Sum	Hard
329	Longest Increasing Path in a Matrix	Hard
330	Patching Array	Hard
332	Reconstruct Itinerary	Hard
335	Self Crossing	Hard
336	Palindrome Pairs	Hard
352	Data Stream as Disjoint Intervals	Hard
354	Russian Doll Envelopes	Hard
358	Rearrange String k Distance Apart	Hard
363	Max Sum of Rectangle No Larger Than K	Hard
381	Insert Delete GetRandom O(1) - Duplicates allowed	Hard
391	Perfect Rectangle	Hard
403	Frog Jump	Hard
407	Trapping Rain Water II	Hard
410	Split Array Largest Sum	Hard
411	Minimum Unique Word Abbreviation	Hard
420	Strong Password Checker	Hard
425	Word Squares	Hard
428	Serialize and Deserialize N-ary Tree	Hard
431	Encode N-ary Tree to Binary Tree	Hard
432	All O`one Data Structure	Hard
440	K-th Smallest in Lexicographical Order	Hard
446	Arithmetic Slices II - Subsequence	Hard
458	Poor Pigs	Hard
460	LFU Cache	Hard
465	Optimal Account Balancing	Hard
466	Count The Repetitions	Hard
471	Encode String with Shortest Length	Hard
472	Concatenated Words	Hard
479	Largest Palindrome Product	Hard
480	Sliding Window Median	Hard
483	Smallest Good Base	Hard
488	Zuma Game	Hard
489	Robot Room Cleaner	Hard
493	Reverse Pairs	Hard
499	The Maze III	Hard
502	IPO	Hard
514	Freedom Trail	Hard
517	Super Washing Machines	Hard
527	Word Abbreviation	Hard
546	Remove Boxes	Hard
548	Split Array with Equal Sum	Hard
552	Student Attendance Record II	Hard
564	Find the Closest Palindrome	Hard
568	Maximum Vacation Days	Hard
587	Erect the Fence	Hard
588	Design In-Memory File System	Hard
591	Tag Validator	Hard
600	Non-negative Integers without Consecutive Ones	Hard
629	K Inverse Pairs Array	Hard
630	Course Schedule III	Hard
631	Design Excel Sum Formula	Hard
632	Smallest Range Covering Elements from K Lists	Hard
639	Decode Ways II	Hard
642	Design Search Autocomplete System	Hard
644	Maximum Average Subarray II	Hard
656	Coin Path	Hard
660	Remove 9	Hard
664	Strange Printer	Hard
668	Kth Smallest Number in Multiplication Table	Hard
675	Cut Off Trees for Golf Event	Hard
679	24 Game	Hard
683	K Empty Slots	Hard
685	Redundant Connection II	Hard
689	Maximum Sum of 3 Non-Overlapping Subarrays	Hard
691	Stickers to Spell Word	Hard
699	Falling Squares	Hard
710	Random Pick with Blacklist	Hard
711	Number of Distinct Islands II	Hard
715	Range Module	Hard
719	Find K-th Smallest Pair Distance	Hard
726	Number of Atoms	Hard
727	Minimum Window Subsequence	Hard
730	Count Different Palindromic Subsequences	Hard
732	My Calendar III	Hard
736	Parse Lisp Expression	Hard
741	Cherry Pickup	Hard
745	Prefix and Suffix Search	Hard
749	Contain Virus	Hard
753	Cracking the Safe	Hard
757	Set Intersection Size At Least Two	Hard
759	Employee Free Time	Hard
761	Special Binary String	Hard
765	Couples Holding Hands	Hard
768	Max Chunks To Make Sorted II	Hard
770	Basic Calculator IV	Hard
772	Basic Calculator III	Hard
773	Sliding Puzzle	Hard
774	Minimize Max Distance to Gas Station	Hard
778	Swim in Rising Water	Hard
780	Reaching Points	Hard
782	Transform to Chessboard	Hard
786	K-th Smallest Prime Fraction	Hard
793	Preimage Size of Factorial Zeroes Function	Hard
798	Smallest Rotation with Highest Score	Hard
801	Minimum Swaps To Make Sequences Increasing	Hard
803	Bricks Falling When Hit	Hard
805	Split Array With Same Average	Hard
810	Chalkboard XOR Game	Hard
815	Bus Routes	Hard
818	Race Car	Hard
827	Making A Large Island	Hard
828	Count Unique Characters of All Substrings of a Given String	Hard
829	Consecutive Numbers Sum	Hard
834	Sum of Distances in Tree	Hard
839	Similar String Groups	Hard
843	Guess the Word	Hard
847	Shortest Path Visiting All Nodes	Hard
850	Rectangle Area II	Hard
854	K-Similar Strings	Hard
857	Minimum Cost to Hire K Workers	Hard
862	Shortest Subarray with Sum at Least K	Hard
864	Shortest Path to Get All Keys	Hard
871	Minimum Number of Refueling Stops	Hard
878	Nth Magical Number	Hard
879	Profitable Schemes	Hard
882	Reachable Nodes In Subdivided Graph	Hard
887	Super Egg Drop	Hard
891	Sum of Subsequence Widths	Hard
895	Maximum Frequency Stack	Hard
899	Orderly Queue	Hard
902	Numbers At Most N Given Digit Set	Hard
903	Valid Permutations for DI Sequence	Hard
906	Super Palindromes	Hard
913	Cat and Mouse	Hard
920	Number of Music Playlists	Hard
924	Minimize Malware Spread	Hard
927	Three Equal Parts	Hard
928	Minimize Malware Spread II	Hard
936	Stamping The Sequence	Hard
940	Distinct Subsequences II	Hard
943	Find the Shortest Superstring	Hard
952	Largest Component Size by Common Factor	Hard
956	Tallest Billboard	Hard
960	Delete Columns to Make Sorted III	Hard
964	Least Operators to Express Number	Hard
968	Binary Tree Cameras	Hard
972	Equal Rational Numbers	Hard
975	Odd Even Jump	Hard
980	Unique Paths III	Hard
982	Triples with Bitwise AND Equal To Zero	Hard
987	Vertical Order Traversal of a Binary Tree	Hard
992	Subarrays with K Different Integers	Hard
995	Minimum Number of K Consecutive Bit Flips	Hard
996	Number of Squareful Arrays	Hard
1000	Minimum Cost to Merge Stones	Hard
1001	Grid Illumination	Hard
1012	Numbers With Repeated Digits	Hard
1028	Recover a Tree From Preorder Traversal	Hard
1032	Stream of Characters	Hard
1036	Escape a Large Maze	Hard
1044	Longest Duplicate Substring	Hard
1063	Number of Valid Subarrays	Hard
1067	Digit Count in Range	Hard
1074	Number of Submatrices That Sum to Target	Hard
1088	Confusing Number II	Hard
1092	Shortest Common Supersequence	Hard
1095	Find in Mountain Array	Hard
1096	Brace Expansion II	Hard
1106	Parsing A Boolean Expression	Hard
1121	Divide Array Into Increasing Sequences	Hard
1125	Smallest Sufficient Team	Hard
1147	Longest Chunked Palindrome Decomposition	Hard
1153	String Transforms Into Another String	Hard
1157	Online Majority Element In Subarray	Hard
1163	Last Substring in Lexicographical Order	Hard
1168	Optimize Water Distribution in a Village	Hard
1172	Dinner Plate Stacks	Hard
1178	Number of Valid Words for Each Puzzle	Hard
1183	Maximum Number of Ones	Hard
1187	Make Array Strictly Increasing	Hard
1192	Critical Connections in a Network	Hard
1199	Minimum Time to Build Blocks	Hard
1203	Sort Items by Groups Respecting Dependencies	Hard
1206	Design Skiplist	Hard
1210	Minimum Moves to Reach Target with Rotations	Hard
1216	Valid Palindrome III	Hard
1220	Count Vowels Permutation	Hard
1223	Dice Roll Simulation	Hard
1224	Maximum Equal Frequency	Hard
1231	Divide Chocolate	Hard
1235	Maximum Profit in Job Scheduling	Hard
1240	Tiling a Rectangle with the Fewest Squares	Hard
1246	Palindrome Removal	Hard
1250	Check If It Is a Good Array	Hard
1255	Maximum Score Words Formed by Letters	Hard
1259	Handshakes That Don't Cross	Hard
1263	Minimum Moves to Move a Box to Their Target Location	Hard
1269	Number of Ways to Stay in the Same Place After Some Steps	Hard
1274	Number of Ships in a Rectangle	Hard
1278	Palindrome Partitioning III	Hard
1284	Minimum Number of Flips to Convert Binary Matrix to Zero Matrix	Hard
1289	Minimum Falling Path Sum II	Hard
1293	Shortest Path in a Grid with Obstacles Elimination	Hard
1298	Maximum Candies You Can Get from Boxes	Hard
1301	Number of Paths with Max Score	Hard
1307	Verbal Arithmetic Puzzle	Hard
1312	Minimum Insertion Steps to Make a String Palindrome	Hard
1316	Distinct Echo Substrings	Hard
1320	Minimum Distance to Type a Word Using Two Fingers	Hard
1326	Minimum Number of Taps to Open to Water a Garden	Hard
1330	Reverse Subarray To Maximize Array Value	Hard
1335	Minimum Difficulty of a Job Schedule	Hard
1340	Jump Game V	Hard
1345	Jump Game IV	Hard
1349	Maximum Students Taking Exam	Hard
1354	Construct Target Array With Multiple Sums	Hard
1359	Count All Valid Pickup and Delivery Options	Hard
1363	Largest Multiple of Three	Hard
1368	Minimum Cost to Make at Least One Valid Path in a Grid	Hard
1373	Maximum Sum BST in Binary Tree	Hard
1377	Frog Position After T Seconds	Hard
1383	Maximum Performance of a Team	Hard
1388	Pizza With 3n Slices	Hard
1392	Longest Happy Prefix	Hard
1397	Find All Good Strings	Hard
1402	Reducing Dishes	Hard
1406	Stone Game III	Hard
1411	Number of Ways to Paint N × 3 Grid	Hard
1416	Restore The Array	Hard
1420	Build Array Where You Can Find The Maximum Exactly K Comparisons	Hard
1425	Constrained Subsequence Sum	Hard
1434	Number of Ways to Wear Different Hats to Each Other	Hard
1439	Find the Kth Smallest Sum of a Matrix With Sorted Rows	Hard
1444	Number of Ways of Cutting a Pizza	Hard
1449	Form Largest Integer With Digits That Add up to Target	Hard
1453	Maximum Number of Darts Inside of a Circular Dartboard	Hard
1458	Max Dot Product of Two Subsequences	Hard
1463	Cherry Pickup II	Hard
1467	Probability of a Two Boxes Having The Same Number of Distinct Balls	Hard
1473	Paint House III	Hard
1478	Allocate Mailboxes	Hard
1483	Kth Ancestor of a Tree Node	Hard
1489	Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree	Hard
1494	Parallel Courses II	Hard
1499	Max Value of Equation	Hard
1505	Minimum Possible Integer After at Most K Adjacent Swaps On Digits	Hard
1510	Stone Game IV	Hard
1515	Best Position for a Service Centre	Hard
1516	Move Sub-Tree of N-Ary Tree	Hard
1520	Maximum Number of Non-Overlapping Substrings	Hard
1521	Find a Value of a Mysterious Function Closest to Target	Hard
1526	Minimum Number of Increments on Subarrays to Form a Target Array	Hard
1531	String Compression II	Hard
1537	Get the Maximum Score	Hard
1542	Find Longest Awesome Substring	Hard
1547	Minimum Cost to Cut a Stick	Hard
1548	The Most Similar Path in a Graph	Hard
1553	Minimum Number of Days to Eat N Oranges	Hard
1563	Stone Game V	Hard
1568	Minimum Number of Days to Disconnect Island	Hard
1569	Number of Ways to Reorder Array to Get Same BST	Hard
1575	Count All Possible Routes	Hard
1579	Remove Max Number of Edges to Keep Graph Fully Traversable	Hard
1585	Check If String Is Transformable With Substring Sort Operations	Hard
1591	Strange Printer II	Hard
1595	Minimum Cost to Connect Two Groups of Points	Hard
1597	Build Binary Expression Tree From Infix Expression	Hard
1601	Maximum Number of Achievable Transfer Requests	Hard
1606	Find Servers That Handled Most Number of Requests	Hard
1610	Maximum Number of Visible Points	Hard
1611	Minimum One Bit Operations to Make Integers Zero	Hard
1617	Count Subtrees With Max Distance Between Cities	Hard
1622	Fancy Sequence	Hard
1627	Graph Connectivity With Threshold	Hard
1632	Rank Transform of a Matrix	Hard
1639	Number of Ways to Form a Target String Given a Dictionary	Hard
1643	Kth Smallest Instructions	Hard
1649	Create Sorted Array through Instructions	Hard
1655	Distribute Repeating Integers	Hard
1659	Maximize Grid Happiness	Hard
1665	Minimum Initial Energy to Finish Tasks	Hard
1671	Minimum Number of Removals to Make Mountain Array	Hard
1675	Minimize Deviation in Array	Hard
1681	Minimum Incompatibility	Hard
1687	Delivering Boxes from Storage to Ports	Hard
1691	Maximum Height by Stacking Cuboids	Hard
1692	Count Ways to Distribute Candies	Hard
1697	Checking Existence of Edge Length Limited Paths	Hard
1703	Minimum Adjacent Swaps for K Consecutive Ones	Hard
1707	Maximum XOR With an Element From Array	Hard
1713	Minimum Operations to Make a Subsequence	Hard
1714	Sum Of Special Evenly-Spaced Elements In Array	Hard
1719	Number Of Ways To Reconstruct A Tree	Hard
1723	Find Minimum Time to Finish All Jobs	Hard
1724	Checking Existence of Edge Length Limited Paths II	Hard
1728	Cat and Mouse II	Hard
1735	Count Ways to Make Array With Product	Hard
1739	Building Boxes	Hard
1745	Palindrome Partitioning IV	Hard
1751	Maximum Number of Events That Can Be Attended II	Hard
1755	Closest Subsequence Sum	Hard
1761	Minimum Degree of a Connected Trio in a Graph	Hard
1766	Tree of Coprimes	Hard
1771	Maximize Palindrome Length From Subsequences	Hard
1776	Car Fleet II	Hard
1782	Count Pairs Of Nodes	Hard
1787	Make the XOR of All Segments Equal to Zero	Hard
1788	Maximize the Beauty of the Garden	Hard
1793	Maximum Score of a Good Subarray	Hard
1799	Maximize Score After N Operations	Hard
1803	Count Pairs With XOR in a Range	Hard
1808	Maximize Number of Nice Divisors	Hard
1815	Maximum Number of Groups Getting Fresh Donuts	Hard
1819	Number of Different Subsequences GCDs	Hard
1825	Finding MK Average	Hard
1830	Minimum Number of Operations to Make String Sorted	Hard
1835	Find XOR Sum of All Pairs Bitwise AND	Hard
1840	Maximum Building Height	Hard
1842	Next Palindrome Using Same Digits	Hard
1847	Closest Room	Hard
1851	Minimum Interval to Include Each Query	Hard
1857	Largest Color Value in a Directed Graph	Hard
1862	Sum of Floored Pairs	Hard
1866	Number of Ways to Rearrange Sticks With K Sticks Visible	Hard
1872	Stone Game VIII	Hard
1879	Minimum XOR Sum of Two Arrays	Hard
1883	Minimum Skips to Arrive at Meeting On Time	Hard
1889	Minimum Space Wasted From Packaging	Hard
1896	Minimum Cost to Change the Final Value of Expression	Hard
1900	The Earliest and Latest Rounds Where Players Compete	Hard
1912	Design Movie Rental System	Hard
1916	Count Ways to Build Rooms in an Ant Colony	Hard
1923	Longest Common Subpath	Hard
1924	Erect the Fence II	Hard
1928	Minimum Cost to Reach Destination in Time	Hard
1931	Painting a Grid With Three Different Colors	Hard
1932	Merge BSTs to Create Single BST	Hard
1938	Maximum Genetic Difference Query	Hard
1944	Number of Visible People in a Queue	Hard
1948	Delete Duplicate Folders in System	Hard
1955	Count Number of Special Subsequences	Hard
1956	Minimum Time For K Virus Variants to Spread	Hard
1960	Maximum Product of the Length of Two Palindromic Substrings	Hard
1964	Find the Longest Valid Obstacle Course at Each Position	Hard
1970	Last Day Where You Can Still Cross	Hard
1977	Number of Ways to Separate Numbers	Hard
1982	Find Array Given Subset Sums	Hard
1987	Number of Unique Good Subsequences	Hard
1994	The Number of Good Subsets	Hard
1998	GCD Sort of an Array	Hard
2003	Smallest Missing Genetic Value in Each Subtree	Hard
2005	Subtree Removal Game with Fibonacci Tree	Hard
2009	Minimum Number of Operations to Make Array Continuous	Hard
2014	Longest Subsequence Repeated k Times	Hard
2019	The Score of Students Solving Math Expression	Hard
2025	Maximum Number of Ways to Partition an Array	Hard
2030	Smallest K-Length Subsequence With Occurrences of a Letter	Hard
2035	Partition Array Into Two Arrays to Minimize Sum Difference	Hard
2040	Kth Smallest Product of Two Sorted Arrays	Hard
2045	Second Minimum Time to Reach Destination	Hard
2050	Parallel Courses III	Hard
2056	Number of Valid Move Combinations On Chessboard	Hard
2060	Check if an Original String Exists Given Two Encoded Strings	Hard
2065	Maximum Path Quality of a Graph	Hard
2071	Maximum Number of Tasks You Can Assign	Hard
2076	Process Restricted Friend Requests	Hard
2081	Sum of k-Mirror Numbers	Hard
2088	Count Fertile Pyramids in a Land	Hard
2092	Find All People With Secret	Hard
2097	Valid Arrangement of Pairs	Hard
2102	Sequentially Ordinal Rank Tracker	Hard
2106	Maximum Fruits Harvested After at Most K Steps	Hard
2111	Minimum Operations to Make the Array K-Increasing	Hard
2117	Abbreviating the Product of a Range	Hard
2122	Recover the Original Array	Hard
2123	Minimum Operations to Remove Adjacent Ones in Matrix	Hard
2127	Maximum Employees to Be Invited to a Meeting	Hard
2132	Stamping the Grid	Hard
2136	Earliest Possible Day of Full Bloom	Hard
2141	Maximum Running Time of N Computers	Hard
2143	Choose Numbers From Two Arrays in Range	Hard
2147	Number of Ways to Divide a Long Corridor	Hard
2151	Maximum Good People Based on Statements	Hard

Year	Day	AdventOfCode
2015	1	Not Quite Lisp
2015	2	I Was Told There Would Be No Math
2015	3	Perfectly Spherical Houses in a Vacuum
2015	4	The Ideal Stocking Stuffer
2015	5	Doesn't He Have Intern-Elves For This?
2015	6	Probably a Fire Hazard
2015	7	Some Assembly Required
2015	8	Matchsticks
2015	9	All in a Single Night
2015	10	Elves Look, Elves Say
2015	11	Corporate Policy
2015	12	JSAbacusFramework.io
2020	1	Report Repair
2020	2	Password Philosophy
2020	3	Toboggan Trajectory
2020	4	Passport Processing
2020	5	Binary Boarding
2020	6	Custom Customs
2020	7	Handy Haversacks
2020	8	Handheld Halting
2020	9	Encoding Error
2020	10	Adapter Array
2020	11	Seating System
2020	12	Rain Risk
2020	13	Shuttle Search
2020	14	Docking Data
2020	15	Rambunctious Recitation
2020	16	Ticket Translation
2020	17	Conway Cubes
2020	18	Operation Order
2020	19	Monster Messages

Division	Year	Round	Google
CodeJam	2008	1	fly swatter
KickStart	2013	1	moist
KickStart	2013	1	captain hammer
KickStart	2013	1	bad horse
KickStart	2020	1	allocation
KickStart	2021	1	k goodness string
KickStart	2021	1	l shaped plots
KickStart	2021	1	rabbit house
KickStart	2021	1	checksum