8 posts.
Ten classic array interview problems with examples, approach, complexity, and clean Python solutions — Two Sum, Best Time to Buy/Sell Stock, Kadane's, Rotate Array, Product Except Self, and more.
Eight classic binary tree interview problems with examples, approach notes, and clean Python solutions — max depth, same tree, invert, symmetric, path sum, LCA, validate BST, and serialize/deserialize.
Six classic bit manipulation problems — Single Number, Number of 1 Bits, Power of Two, Counting Bits, Missing Number, Reverse Bits — plus the tricks that make them tick: n & (n-1), n & -n, and XOR cancellation.
Eight classic dynamic programming problems — Climbing Stairs, House Robber, Coin Change, LIS, Word Break, 0/1 Knapsack, Edit Distance, and LCS — each with Python solutions and DP tables.
Eight classic hash map problems with worked Python solutions — Two Sum, Group Anagrams, Subarray Sum Equals K, Longest Consecutive Sequence, Top K Frequent Elements, and more.
Eight classic linked-list interview problems — reverse, detect cycle, merge sorted lists, remove Nth from end, cycle start, palindrome, add two numbers, and intersection — each with a worked Python solution.
Eight classic stack and queue interview problems with worked Python solutions — Valid Parentheses, Min Stack, Daily Temperatures, Sliding Window Maximum, and more.
Eight classic string problems with worked Python solutions — Valid Anagram, Group Anagrams, Longest Substring Without Repeating Characters, Longest Palindromic Substring, and more.