Coding Interview Problems

339. Nested List Weight Sum

Problem Statement This problem gives you a nested list of integers called nestedList, where each element is represented by the...

378. Kth Smallest Element in a Sorted Matrix

At first glance, this problem looks like a simple sorting task, but the real learning begins when you try to...

560. Subarray Sum Equals K

Problem Statement You’re given an integer array nums and an integer k. Your task is to count how many contiguous,...

236. Lowest Common Ancestor of a Binary Tree

Problem Statement You’re given the root of a binary tree and two distinct nodes p and q that are guaranteed...

198. House Robber

The House Robber problem is a classic introduction to Dynamic Programming. It is a favorite among interviewers at companies like...

110. Balanced Binary Tree

Checking if a tree is balanced is a fundamental skill frequently tested by giants like Google, Meta, and Amazon. It...

55. Jump Game

Problem Statement You’re given an array nums where nums[i] tells you the farthest you’re allowed to jump forward from index i. Starting at index $0$, determine...

64. Minimum Path Sum

Problem Statement You are given an m x n grid of non-negative integers. Starting at the top-left cell (0, 0),...

20. Valid Parentheses

Problem Statement You are given a string s that contains only the characters '(', ')', '{', '}', '[', and ']',...

26. Remove Duplicates from Sorted Array

Removing duplicates from a sorted array is a fundamental array-manipulation problem frequently asked in interviews at companies like Google and...

300. Longest Increasing Subsequence

The Longest Increasing Subsequence (LIS) problem is a classic interview question frequently asked by top companies like Google, Amazon, and...

2327. Number of People Aware of a Secret

This is a Dynamic Programming problem that focuses on "states" and "time intervals." It simulates a growth process where individuals...