algorithms LeetCode Category Problem Base 53. Maximum Subarray Tree 235. Lowest Common Ancestor of a Binary Search Tree 199. Binary Tree Right Side View 99. Recover Binary Search Tree 669. Trim a Binary Search Tree 450. Delete Node in a BST 687. Longest Univalue Path 103. Binary Tree Zigzag Level Order Traversal 110. Balanced Binary Tree 1361. Validate Binary Tree Nodes 127. Word Ladder 297. Serialize and Deserialize Binary Tree 543. Diameter of Binary Tree 1609. Even Odd Tree 662. Maximum Width of Binary Tree 814. Binary Tree Pruning 1325. Delete Leaves With a Given Value 637. Average of Levels in Binary Tree 116. Populating Next Right Pointers in Each Node 2477. Minimum Fuel Cost to Report to the Capital 1376. Time Needed to Inform All Employees 107. Binary Tree Level Order Traversal II 951 Flip Equivalent Binary Trees 617. Merge Two Binary Trees Design 1146. Snapshot Array 1396. Design Underground System 460. LFU Array 22. Generate Parentheses 703. Kth Largest Element in a Stream 925. Long Pressed Name 1833. Maximum Ice Cream Bars 2653. Sliding Subarray Beauty 1079. Letter Tile Possibilities 31. Next Permutation 283 Move Zeroes 540. Single Element in a Sorted Array 33. Search in Rotated Sorted Array 819. Most Common Word 565. Array Nesting 3. Longest Substring Without Repeating Characters 1743. Restore the Array From Adjacent Pairs 120. Triangle 981. Time Based Key-Value Store 118. Pascal's Triangle 56. Merge Intervals 881. Boats to Save People 239. Sliding Window Maximum 304. Range Sum Query 2D - Immutable 146. LRU Cache 2007. Find Original Array From Doubled Array 45. Jump Game II 128. Longest Consecutive Sequence 215. Kth Largest Element in an Array 986. Interval List Intersections 17. Letter Combinations of a Phone Number 680. Valid Palindrome II 733. Flood Fill 49. Group Anagrams 42. Trapping Rain Water 200. Number of Islands 1423. Maximum Points You Can Obtain from Cards 973. K Closest Points to Origin 1608. Special Array With X Elements Greater Than or Equal X 724. Find Pivot Index 438. Find All Anagrams in a String 93. Restore IP Addresses 448. Find All Numbers Disappeared in an Array 1046. Last Stone Weight 436. Find Right Interval 442. Find All Duplicates in an Array 904 Fruit into baskets 347. Top K Frequent Elements 2070. Most Beautiful Item for Each Query 240. Search a 2D Matrix II 524. Longest Word in Dictionary through Deleting 130. Surrounded Regions 27. Remove Element 84. Largest Rectangle in Histogram 678. Valid Parenthesis String 12. Integer to Roman 289. Game of Life 41. First Missing Positive Linkedlist 2. Add Two Numbers 86. Partition List 1019. Next Greater Node In Linked List Backtracking 542. 01 Matrix 78. Subsets 140. Word Break II 77. Combinations 1631. Path With Minimum Effort 473. Matchsticks to Square 842. Split Array into Fibonacci Sequence 51. N-Queens 980. Unique Paths III 301. Remove Invalid Parentheses 494. Target Sum 39. Combination Sum 79. Word Search 216. Combination Sum III 332. Reconstruct Itinerary 40. Combination Sum II 698. Partition to K Equal Sum Subsets Graph 1202. Smallest String With Swaps 847. Shortest Path Visiting All Nodes 417. Pacific Atlantic Water Flow 463. Island Perimeter 743. Network Delay Time 827. Making A Large Island 2101. Detonate the Maximum Bombs 721. Accounts Merge 785. Is Graph Bipartite 1584. Min Cost to Connect All Points 787. Cheapest Flights Within K Stops 207. Course Schedule 329. Longest Increasing Path in a Matrix Recursive 62. Unique Paths 695. Max Area of Island 1. Mark all the visited cells 2. Traverse the cells with value 1 recursively, and calculate 124. Binary Tree Maximum Path Sum 1448. Count Good Nodes in Binary Tree 437. Path Sum III 341. Flatten Nested List Iterator 63. Unique Paths II 64. Minimum Path Sum 112. Path Sum 129. Sum Root to Leaf Numbers 113. Path Sum II Search 1011. Capacity To Ship Packages Within D Days 1802. Maximum Value at a Given Index in a Bounded Array 2812. Find the Safest Path in a Grid 2616. Minimize the Maximum Difference of Pairs Concurrency 1114. Print in Order 1115 Print FooBar Alternately Divide_conquer 218. The Skyline Problem Trie 211. Add and Search Word - Data structure design 1268. Search Suggestions System 745. Prefix and Suffix Search 720. Longest Word in Dictionary 208. Implement Trie Greedy 1642. Furthest Building You Can Reach 68. Text Justification 502. IPO Sorting 462. Minimum Moves to Equal Array Elements II 451. Sort Characters By Frequency 791. Custom Sort String Queue 622. Design Circular Queue String 459. Repeated Substring Pattern 763. Partition Labels 890. Find and Replace Pattern Dynamicpro 279. Perfect Squares 1048. Longest String Chain 139. Word Break 2707. Extra Characters in a String 1416. Restore The Array 823. Binary Trees With Factors 392. Is Subsequence 85. Maximal Rectangle 1359. Count All Valid Pickup and Delivery Options 377. Combination Sum IV 300. Longest Increasing Subsequence 474. Ones and Zeroes 1043. Partition Array for Maximum Sum 322. Coin Change Stack 224. Basic Calculator 739. Daily Temperatures 394. Decode String 71. Simplify Path 844. Backspace String Compare 20. Valid Parentheses 225. Implement Stack using Queues