Coding Problems

Generate an n×n matrix filled with numbers from 1 to n² in spiral order (clockwise from outside to inside).

Given a list of time intervals, merge all overlapping intervals and return the merged intervals sorted by start time.

Given a binary tree and a target sum, determine if there exists a root-to-leaf path where the sum of node values equals...

Count the frequency of each word in a given text and return the top k most frequent words in descending order of frequen...

Given a string s containing just the characters "(", ")", "{", "}", "[" and "]", determine if the input string is valid....

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and...

The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is th...

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target...

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the si...

Given an integer x, return true if x is palindrome integer. An integer is a palindrome when it reads the same backward a...