This folder contains the introductory problems from each category of the NeetCode 50 list. These are designed to be solved slowly and methodically to build a strong foundation.
- Contains Duplicate - Check if array contains duplicates
- Valid Anagram - Check if two strings are anagrams
- Two Sum - Find two numbers that add up to target
- Valid Palindrome - Check if string is palindrome
- Two Sum II - Two sum on sorted array
- Best Time to Buy and Sell Stock - Find max profit from stock prices
- Valid Parentheses - Check if parentheses are valid
- Binary Search - Classic binary search implementation
- Reverse Linked List - Reverse a linked list
- Invert Binary Tree - Invert a binary tree
- Implement Trie (Prefix Tree) - Implement a trie data structure
- Combination Sum - Find all combinations that sum to target
- Number of Islands - Count islands in a grid
- Climbing Stairs - Count ways to climb stairs
- Unique Paths - Count unique paths in grid
- Maximum Subarray - Find maximum sum subarray
- Insert Interval - Insert and merge intervals
- Rotate Image - Rotate 2D matrix 90 degrees
- Number of 1 Bits - Count set bits in number
- Work through problems in order, one category at a time
- Read the problem description in each folder
- Try solving it yourself first
- Review the solution template if stuck
- Add your own notes and insights