1. Arrays
  2. _**String
  3. _**2Pointer
    1. Sort Colors
  4. _**Prefix Sum
    1. Product of Array Except Self
  5. _**Queue
  6. _**Stack 1.
  7. _**LinkedList
  8. _**Binary Tree BFS DFS Lowest Common Ancestor of a Binary Tree
  9. _**Graph
    1. Course Schedule ,Topological sort BFS
  10. _**Binary Search
    1. Search in Rotated Sorted Array 3._**Recursion
    2. recursion basic
    3. recursion multi function call
    4. Print number of subsequence with sum K
    5. Print all Subsequence where sum =K
    6. Merge Sort
    7. Combination Sum
    8. Combination Sum 2
  11. _**BackTracking
  12. _**DP
  13. _**DP -1D
  14. _**DP-2D
    1. Partition Equal Subset Sum
  15. _**DP on subsequence and subsets
  16. _**DP on Stock 121. Best Time to Buy and Sell Stock
  17. _**Bit Manipulation
  18. _**Trie
  19. _**Binary Search tree
  20. _**Matrix
    1. Number of Islands
    2. Rotting Orange