Blind75

The canonical 75-problem Blind 75 subset of the Neetcode curriculum: enough breadth to OA-prep without the long tail. Worked solutions and prose live here; the full 150-problem expansion (with stub links back into this page for shared problems) is on Blind150.

Arrays#

Contains Duplicate#

Contains Duplicate on Leetcode

Valid Anagram#

Valid Anagram on Leetcode

Two Sum#

Two Sum on Leetcode

Group Anagrams#

Group Anagrams on Leetcode

Top K Frequent Elements#

Top K Frequent Elements on Leetcode

Product of Array Except Self#

Product of Array Except Self on Leetcode

Encode and Decode Strings#

Encode and Decode Strings on Leetcode (★ Premium)

Graph#

Longest Consecutive Sequence#

Longest Consecutive Sequence on Leetcode

Two Pointers#

Valid Palindrome#

Valid Palindrome on Leetcode

3Sum#

3Sum on Leetcode

Container with Most Water#

Container with Most Water on Leetcode

Sliding Window#

Best Time to Buy & Sell Stock#

Best Time to Buy & Sell Stock on Leetcode

Longest Substring Without Repeating Characters#

Longest Substring Without Repeating Characters on Leetcode

Longest Repeating Character Replacement#

Longest Repeating Character Replacement on Leetcode

Minimum Window Substring#

Minimum Window Substring on Leetcode

Stack#

Valid Parentheses#

Valid Parentheses on Leetcode

Binary Search#

Search Rotated Sorted Array#

Search Rotated Sorted Array on Leetcode

Find Minimum in Rotated Sorted Array#

Find Minimum in Rotated Sorted Array on Leetcode

Linked List#

Reverse Linked List#

Reverse Linked List on Leetcode

Merge Two Linked Lists#

Merge Two Linked Lists on Leetcode

Reorder List#

Reorder List on Leetcode

Remove Nth Node from End of List#

Remove Nth Node from End of List on Leetcode

Linked List Cycle#

Linked List Cycle on Leetcode

Merge K Sorted Lists#

Merge K Sorted Lists on Leetcode

Trees#

Invert Binary Tree#

Invert Binary Tree on Leetcode

Maximum Depth of Binary Tree#

Maximum Depth of Binary Tree on Leetcode

Same Tree#

Same Tree on Leetcode

Subtree of Another Tree#

Subtree of Another Tree on Leetcode

Lowest Common Ancestor of a BST#

Lowest Common Ancestor of a BST on Leetcode

Binary Tree Level Order Traversal#

Binary Tree Level Order Traversal on Leetcode

Validate Binary Search Tree#

Validate Binary Search Tree on Leetcode

Kth Smallest Element in a BST#

Kth Smallest Element in a BST on Leetcode

Construct Tree from Preorder and Inorder Traversal#

Construct Tree from Preorder and Inorder Traversal on Leetcode

Binary Tree Max Path Sum#

Binary Tree Max Path Sum on Leetcode

Serialize and Deserialize Binary Tree#

Serialize and Deserialize Binary Tree on Leetcode

Tries#

Implement Trie#

Implement Trie on Leetcode

Design Add and Search Word Data Structure#

Design Add and Search Word Data Structure on Leetcode

Word Search II#

Word Search II on Leetcode

Heap / Priority Queue#

Find Median from Data Stream#

Find Median from Data Stream on Leetcode

Backtracking#

Combination Sum#

Combination Sum on Leetcode

Word Search#

Word Search on Leetcode

Graphs#

Number of Islands#

Number of Islands on Leetcode

Clone Graph#

Clone Graph on Leetcode

Pacific Atlantic Waterflow#

Pacific Atlantic Waterflow on Leetcode

Course Schedule#

Course Schedule on Leetcode

Number of Connected Components in Graph#

Number of Connected Components in Graph on Leetcode (★ Premium)

Graph Valid Tree#

Graph Valid Tree on Leetcode (★ Premium)

Advanced Graphs#

Alien Dictionary#

Alien Dictionary on Leetcode (★ Premium)

1-D Dynamic Programming#

Climbing Stairs#

Climbing Stairs on Leetcode

House Robber#

House Robber on Leetcode

House Robber II#

House Robber II on Leetcode

Longest Palindromic Substring#

Longest Palindromic Substring on Leetcode

Palindromic Substrings#

Palindromic Substrings on Leetcode

Decode Ways#

Decode Ways on Leetcode

Coin Change#

Coin Change on Leetcode

Maximum Product Subarray#

Maximum Product Subarray on Leetcode

Word Break#

Word Break on Leetcode

Longest Increasing Subsequence#

Longest Increasing Subsequence on Leetcode

2-D Dynamic Programming#

Unique Paths#

Unique Paths on Leetcode

Longest Common Subsequence#

Longest Common Subsequence on Leetcode

Greedy#

Maximum Subarray#

Maximum Subarray on Leetcode

Jump Game#

Jump Game on Leetcode

Intervals#

Insert Interval#

Insert Interval on Leetcode

Merge Intervals#

Merge Intervals on Leetcode

Non-Overlapping Intervals#

Non-Overlapping Intervals on Leetcode

Meeting Rooms#

Meeting Rooms on Leetcode (★ Premium)

Meeting Rooms II#

Meeting Rooms II on Leetcode (★ Premium)

Math & Geometry#

Rotate Image#

Rotate Image on Leetcode

Spiral Matrix#

Spiral Matrix on Leetcode

Set Matrix Zeroes#

Set Matrix Zeroes on Leetcode

Bit Manipulation#

Number of 1 Bits#

Number of 1 Bits on Leetcode

Counting Bits#

Counting Bits on Leetcode

Reverse Bits#

Reverse Bits on Leetcode

Missing Number#

Missing Number on Leetcode

Sum of Two Integers#

Sum of Two Integers on Leetcode