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Featured Challenges

Dive into a variety of problems to test your coding prowess.

Two Sum

Easy

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

15 min Array, Hash Table
85% Solved Start Challenge

Longest Substring Without Repeating Characters

Medium

Given a string s, find the length of the longest substring without repeating characters.

30 min String, Sliding Window
55% Solved Start Challenge

Merge k Sorted Lists

Hard

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list and return it.

60 min Linked List, Heap
20% Solved Start Challenge
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Problem: Reverse String

Easy
1 function reverseString(s: string): string {
2 // Your code here
3 return s.split('').reverse().join('');
4 }
5
6 console.log(reverseString("hello")); // Output: "olleh"
7
8

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Rank Developer Score Problems Solved
1 AliceCoder 1500 200
2 DevMaster 1450 190
3 CodeGuru 1400 185
4 PixelDev 1380 180
5 LogicQueen 1350 175