Blind 75

The classic 75 problems that cover the highest-ROI patterns for coding interviews. Work through these before grinding hundreds of random problems.

74 problems available in AlgoForge catalog

#	Title	Difficulty	Topics
1	Two Sum	Easy	hash table
121	Best Time to Buy and Sell Stock	Easy	array
217	Contains Duplicate	Easy	hash table
238	Product of Array Except Self	Medium	array
53	Maximum Subarray	Easy	dynamic programming
152	Maximum Product Subarray	Medium	dynamic programming
153	Find Minimum in Rotated Sorted Array	Medium	binary search
33	Search in Rotated Sorted Array	Medium	binary search
15	3 Sum	Medium	two pointers
11	Container With Most Water	Medium	greedy
371	Sum of Two Integers	Easy	bit manipulation
191	Number of 1 Bits	Easy	bit manipulation
338	Counting Bits	Medium	math
268	Missing Number	Medium	bit manipulation
190	Reverse Bits	Easy	bit manipulation
70	Climbing Stairs	Easy	dynamic programming
322	Coin Change	Medium	dynamic programming
300	Longest Increasing Subsequence	Medium	binary search
1143	Longest Common Subsequence	Medium	dynamic programming
139	Word Break	Medium	dynamic programming
39	Combination Sum	Medium	backtracking
198	House Robber	Easy	dynamic programming
213	House Robber II	Medium	dynamic programming
91	Decode Ways	Medium	dynamic programming
62	Unique Paths	Medium	dynamic programming
55	Jump Game	Medium	greedy
133	Clone Graph	Medium	breadth first search
207	Course Schedule	Medium	breadth first search
417	Pacific Atlantic Water Flow	Medium	depth first search
200	Number of Islands	Medium	depth first search
128	Longest Consecutive Sequence	Hard	array
269	Alien Dictionary	Hard	breadth first search
261	Graph Valid Tree	Medium	breadth first search
323	Number of Connected Components in an Undirected Graph	Medium	hash table
57	Insert Interval	Hard	sort
56	Merge Intervals	Hard	sort
435	Non-overlapping Intervals	Medium	greedy
252	Meeting Rooms	Easy	sort
253	Meeting Rooms II	Medium	sort
206	Reverse Linked List	Easy	linked list
141	Linked List Cycle	Easy	two pointers
21	Merge Two Sorted Lists	Easy	linked list
23	Merge k Sorted Lists	Hard	linked list
19	Remove Nth Node From End of List	Medium	two pointers
143	Reorder List	Medium	two pointers
73	Set Matrix Zeroes	Medium	array
54	Spiral Matrix	Medium	array
48	Rotate Image	Medium	array
79	Word Search	Medium	backtracking
3	Longest Substring Without Repeating Characters	Medium	hash table
424	Longest Repeating Character Replacement	Medium	two pointers
76	Minimum Window Substring	Hard	hash table
242	Valid Anagram	Easy	string
49	Group Anagrams	Medium	hash table
20	Valid Parentheses	Easy	stack
125	Valid Palindrome	Easy	string
5	Longest Palindromic Substring	Medium	string
647	Palindromic Substrings	Medium	string
271	Encode and Decode Strings	Medium	string
104	Maximum Depth of Binary Tree	Easy	recursion
100	Same Tree	Easy	recursion
226	Invert Binary Tree	Easy	tree
124	Binary Tree Maximum Path Sum	Hard	recursion
102	Binary Tree Level Order Traversal	Easy	breadth first search
297	Serialize and Deserialize Binary Tree	Hard	tree
572	Subtree of Another Tree	Easy	tree
105	Construct Binary Tree from Preorder and Inorder Traversal	Medium	recursion
98	Validate Binary Search Tree	Medium	recursion
230	Kth Smallest Element in a BST	Medium	binary search tree
235	Lowest Common Ancestor of a Binary Search Tree	Easy	binary search tree
208	Implement Trie (Prefix Tree)	Medium	tree
212	Word Search II	Hard	backtracking
347	Top K Frequent Elements	Medium	sort
295	Find Median from Data Stream	Hard	binary heap