DataStructure and Algorithm

One stop for Data Structure and Algorithms along with problems related to it. It will help anyone who wants to learn about Data Structure / Algorithm.

Data Structures:

1. Array

a.	Dynamic Array
b.	Multi-Dimension Array
c.	Different Array Problems
d.	Circular Array
e.	Java Array methods : Array Slicing etc

2. Linked List:

a.	Singly Linked List
b.	Doubly Linked List
c.	Different Linked List Problems

3. Stacks:

a.	Design and Implement Stack
b.	Different Stacks Problems

4. Queues:

a.	Design and Implement Queue
b.	Different Queues Problems

5. Hashing:

a.	Index Mapping or Trivial Hashing
b.	Separate Chaining for Collision Handling
c.	Double Hashing
d.	Hash Map / Hash Table
e.	Java Hashes
f.	Different Hashing Problems

6. Trees | Graphs

a.	Binary Tree
b.	Binary Search Tree
c.	Heap
d.	Trie
e.	Graphs:
        i. A graph G is an ordered pair of a set V of vertices and a set E of edges. G = (V,E])
        ii. Number of Edges: 
                1. Directed: |V| = n then 0 <= |E| <= n (n-1)
                2. Undirected: O <= |E| <= n(n-1)/2
f.	Shortest Paths
g.	BFS [Using Queue]
h.	DFS [Using Stack]
        i. Pre-Order [Root, Left, Right]
        ii. In-Order [Left, Root, Right] -> It gives a sorted list for BST
        iii. Post-Order [Left, Right, Root]
i.	Dijkstra
j.	Different Tree/Graph Problems

7. Java Collection:

a.	Set -> HashSet, LinkedHashSet, TreeSet
b.	List -> LinkedList & ArrayList
c.	Queue -> Priority Queue (FIFO)
d.	Deque -> ArrayDeque (FIFO or LIFO)
e.	Map -> HashMap, LinkedHashMap,TreeMap
f.	HashTable
g.	Enum
h.	Collections Class
i.	Sorting Collections
j.	Comparable vs Comparator

Algorithm:

1. Sorting

a.	Divide and Conquer 
        i. Merge Sort
        ii. Quick Sort
        iii. Heap Sort
b.	Regular Sort
        i. Bubble Sort – Iterative/Recursive
        ii. Selection Sort
        iii. Insertion Sort – Iterative/Recursive
c.	Counting Sort
d.	Java Sorting Built In examples

2. Searching

a.	Linear Search
b.	Binary Search - Iterative/Recursive
c.	Fibonacci Search
d.	Java Searching Built in Examples

3. Greedy Method

Big (O) :

[1 < logn < √ n < n < nlogn < n^2 < n^3 < ... < 2^n < 3^n < n^n]

O(1) – Constant
O(logn) – Logarithmic
O(n) – Linear
O(n2) – Quadratic
O(n3) – Cubic
O(2n) – Exponential

Different Algorithms with simple Big(O) analysis

ASCII Char : In Decimal

[0 - 127] -> [All Regular Characters]

[128 - 255] -> [Extended ASCII]

[0 - 31] -> [control char]

[32 - 127] -> [printable char]

[48 - 57] -> [0 - 9]

[65 - 90] -> [A - Z]

[97 - 122] -> [a - z]

[128 - 255] -> [extended char]

Data Measurement

Data Measurement Size

Bit -> Binary Digit (1 or 0)

Byte -> 8 bits

Kilobyte (KB) -> 1,024 Bytes

Megabyte (MB) -> 1,024 Kilobytes

Gigabyte (GB) -> 1,024 Megabytes

Terabyte (TB) -> 1,024 Gigabytes

Petabyte (PB) -> 1,024 Terabytes

Exabyte (EB) -> 1,024 Petabytes

Java's primitive data types

byte -> 1 byte | -128 to 127

short -> 2 bytes | -32,768 to 32,767

int -> 4 bytes | -2,147,483,648 to 2,147,483, 647

long -> 8 bytes | -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

float -> 4 bytes | approximately ±3.40282347E+38F (6-7 significant decimal digits) Java implements IEEE 754 standard

double -> 8 bytes | approximately ±1.79769313486231570E+308 (15 significant decimal digits)

char -> 2 byte | 0 to 65,536 (unsigned)

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