Microsoft Coding Interview Questions

Classic DSA with trees, DP, and string processing.

#	Title	Difficulty	Topics
1	Two Sum	Easy	hash table
2	Add Two Numbers	Medium	linked list
4	Median of Two Sorted Arrays	Hard	binary search
5	Longest Palindromic Substring	Medium	string
8	String to Integer (atoi)	Easy	string
15	3 Sum	Medium	two pointers
17	Letter Combinations of a Phone Number	Medium	backtracking
19	Remove Nth Node From End of List	Medium	two pointers
20	Valid Parentheses	Easy	stack
21	Merge Two Sorted Lists	Easy	linked list
22	Generate Parentheses	Medium	backtracking
23	Merge k Sorted Lists	Hard	linked list
33	Search in Rotated Sorted Array	Medium	binary search
39	Combination Sum	Medium	backtracking
40	Combination Sum II	Medium	backtracking
46	Permutations	Medium	backtracking
48	Rotate Image	Medium	array
51	N-Queens	Hard	backtracking
53	Maximum Subarray	Easy	dynamic programming
67	Add Binary	Easy	string
73	Set Matrix Zeroes	Medium	array
74	Search a 2D Matrix	Medium	binary search
75	Sort Colors	Medium	sort
77	Combinations	Medium	backtracking
79	Word Search	Medium	backtracking
80	Remove Duplicates from Sorted Array II	Medium	array
82	Remove Duplicates from Sorted List II	Medium	linked list
86	Partition List	Medium	two pointers
91	Decode Ways	Medium	dynamic programming
92	Reverse Linked List II	Medium	linked list
93	Restore IP Addresses	Medium	backtracking
94	Binary Tree Inorder Traversal	Medium	tree
97	Interleaving String	Hard	dynamic programming
98	Validate Binary Search Tree	Medium	recursion
99	Recover Binary Search Tree	Hard	tree
101	Symmetric Tree	Easy	stack
102	Binary Tree Level Order Traversal	Easy	breadth first search
103	Binary Tree Zigzag Level Order Traversal	Medium	breadth first search
105	Construct Binary Tree from Preorder and Inorder Traversal	Medium	recursion
106	Construct Binary Tree from Inorder and Postorder Traversal	Medium	recursion
107	Binary Tree Level Order Traversal II	Easy	breadth first search
108	Convert Sorted Array to Binary Search Tree	Medium	recursion
109	Convert Sorted List to Binary Search Tree	Medium	recursion
111	Minimum Depth of Binary Tree	Easy	recursion
112	Path Sum	Easy	depth first search
113	Path Sum II	Medium	depth first search
114	Flatten Binary Tree to Linked List	Medium	recursion
116	Populating Next Right Pointers in Each Node	Medium	recursion
117	Populating Next Right Pointers in Each Node II	Hard	breadth first search
120	Triangle	Medium	dynamic programming
121	Best Time to Buy and Sell Stock	Easy	array
123	Best Time to Buy and Sell Stock III	Hard	dynamic programming
124	Binary Tree Maximum Path Sum	Hard	recursion
125	Valid Palindrome	Easy	string
129	Sum Root to Leaf Numbers	Medium	recursion
134	Gas Station	Medium	greedy
136	Single Number	Easy	bit manipulation
138	Copy List with Random Pointer	Medium	linked list
141	Linked List Cycle	Easy	two pointers
142	Linked List Cycle II	Medium	two pointers
144	Binary Tree Preorder Traversal	Medium	tree
145	Binary Tree Postorder Traversal	Hard	tree
146	LRU Cache	Hard	design
151	Reverse Words in a String	Medium	string
153	Find Minimum in Rotated Sorted Array	Medium	binary search
160	Intersection of Two Linked Lists	Easy	linked list
162	Find Peak Element	Medium	binary search
165	Compare Version Numbers	Easy	string
168	Excel Sheet Column Title	Easy	math
169	Majority Element	Easy	array
171	Excel Sheet Column Number	Easy	math
173	Binary Search Tree Iterator	Medium	design
174	Dungeon Game	Hard	dynamic programming
189	Rotate Array	Easy	array
191	Number of 1 Bits	Easy	bit manipulation
199	Binary Tree Right Side View	Medium	depth first search
200	Number of Islands	Medium	depth first search
203	Remove Linked List Elements	Easy	linked list
204	Count Primes	Easy	hash table
206	Reverse Linked List	Easy	linked list
208	Implement Trie (Prefix Tree)	Medium	tree
213	House Robber II	Medium	dynamic programming
215	Kth Largest Element in an Array	Medium	array
218	The Skyline Problem	Hard	sort
227	Basic Calculator II	Medium	stack
230	Kth Smallest Element in a BST	Medium	binary search tree
232	Implement Queue using Stacks	Easy	stack
234	Palindrome Linked List	Easy	linked list
235	Lowest Common Ancestor of a Binary Search Tree	Easy	binary search tree
236	Lowest Common Ancestor of a Binary Tree	Medium	depth first search
237	Delete Node in a Linked List	Easy	linked list
238	Product of Array Except Self	Medium	array
240	Search a 2D Matrix II	Medium	array
258	Add Digits	Easy	math
268	Missing Number	Medium	bit manipulation
287	Find the Duplicate Number	Hard	two pointers
300	Longest Increasing Subsequence	Medium	binary search
322	Coin Change	Medium	dynamic programming
344	Reverse String	Easy	two pointers
373	Find K Pairs with Smallest Sums	Medium	binary heap
387	First Unique Character in a String	Easy	hash table
419	Battleships in a Board	Medium	array
443	String Compression	Easy	string
445	Add Two Numbers II	Medium	linked list
449	Serialize and Deserialize BST	Medium	binary search tree
452	Minimum Number of Arrows to Burst Balloons	Medium	greedy
650	2 Keys Keyboard	Medium	dynamic programming
651	4 Keys Keyboard	Medium	math
672	Bulb Switcher II	Medium	math
819	Most Common Word	Easy	string
863	All Nodes Distance K in Binary Tree	Medium	tree