Tree
Divide and conquer
912. Sort an Array Merge Sort
153. Find Minimum in Rotated Sorted Array Binary Search
Linked List
Binary Search Tree (BST)
108. Convert Sorted Array to Binary Search Tree Recursion + Divide and Conquer
230. Kth Smallest Element in a BST
700. Search in a Binary Search Tree
Graph
841. Keys and Rooms (DFS)
200. Number of Islands Traverse connected components (DFS)
133. Clone Graph Queue + Hashtable
Search / Backtracking (DFS/BFS)
79. Search Word (DFS)
17. Letter Combinations of a Phone Number Combination
37. Sudoku Solver (DFS)
Binary Search
99. Recover Binary Search Tree
Two Pointers
977. Squares of a Sorted Array (QuickSort/MergeSort)
167. Two Sum II – Input array is sorted
Dynamic Programing
To be continue…