SlaveCode.

Your code is your master.
Serve it well.

Stop thinking and start delivering. The industry doesn't want your creativity; it wants your total submission to the roadmap. Survive the whip of the grind and prove you have the grit to be a top-tier unit of labor.

Problems Compilers

1. Two Sum

Easy

Array

Hash Table

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice. You can return the answer in any order.

Example 1

Input: nums = [2,7,11,15], target = 9

Output: [0,1]

// Because nums[0] + nums[1] = 9

Example 2

Input: nums = [3,2,4], target = 6

Output: [1,2]

// Because nums[1] + nums[2] = 6

Constraints

2 <= nums.length <= 104
-109 <= nums[i] <= 109
-109 <= target <= 109
Only one valid answer exists.

JAVA

 class Solution {
    public int[] twoSum(int[] nums, int target) {
        HashMap<Integer, Integer> map = new HashMap<>();
        
        for (int i = 0; i < nums.length; i++) {
            int complement = target - nums[i];
            
            if (map.containsKey(complement)) {
                return new int[] { map.get(complement), i };
            }
            
            map.put(nums[i], i);
        }
        
        return new int[] {};
    }
}

Everything you need to compete and grow.

A unified platform built around the developer's journey — from your first algorithm to your first arena win.

Practice Mode

1. 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.

Input: nums = [2,7,11,15], target = 9

Output: [0,1]

Python

def two_sum(nums, target):
    seen = {}
    for i, n in enumerate(nums):
        diff = target - n
        if diff in seen:
            return [seen[diff], i]
        seen[n] = i

The Arena

Timed Matches

Compete against other coders on the exact same problem, racing the clock.

Shared Challenge

All participants receive the same challenge simultaneously.

Live Leaderboards

Watch ranks shift in real-time as test cases pass and coders submit.

Arena Lobby

Host Match

Create private matches

Join Room

Enter access code

Compiler

#include <iostream>

int main() {
    std::cout << "Hello Arena";
    return 0;
}

Output

Your journey, quantified in real-time.

SlaveCode tracks every line you write and every battle you win to build your global developer identity.

XYZ XYZ

xyz11

Rank

3,14,914

15Following

60Followers

Recent Submissions

Two Sum

2 mins ago

Java

Accepted

Longest Substring Without Repeating

14 mins ago

Rust

Wrong Answer

Median of Two Sorted Arrays

45 mins ago

Cpp

Time Limit

Add Two Numbers

1 hour ago

Accepted

Longest Palindromic Substring

2 hours ago

Accepted

Total Submissions1,242

Network

Social Activity

Followers

Following

Alex Rivera

arivera

Sarah Chen

schen_dev

Marcus Thorne

mthorne

1220/3191

Solved

4 Attempting

Easy

408/850

Medium

692/1621

Hard

120/720

Arena Records

Match History

32 TOTAL

Median of Two Sorted Arrays

Hard

2h ago • C++

Rank1

Longest Palindrome

Medium

5h ago • go

Rank2

Two Sum

Easy

1d ago • rust

Rank1

Median of Two Sorted Arrays

Hard

2d ago • java

Rank4

Longest Palindromic Substring

Medium

3d ago • rust

Rank7

1,242submissions in the past one year

Total active days:184

Current streak:

Max streak:42

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb

Mar

Apr

May

Host a Match

Create a private arena and invite your friends to a real-time coding battle.

Join Arena

Enter an invite code to join an existing match and test your skills.

AB12XY

Define the Battlefield

Orchestrate competitive environments at scale. Whether hosting a private 1v1 duel or a 50-player tournament, our engine handles the orchestration while you define the difficulty, language constraints, and problem topics.

Customizable Match Logic

Instant Room Generation

Topic-Specific Filtering

20 mins

Start Match

Arena Lobby

Maximum Sum Path Challenge

Medium

Java

Invite Code

82XJ-72

Participants

4 / 50

John Carter

Host

johncarter

Alicia Brownaliciab

Ravi Vermaraviv

Sharukh Khansharukhkhan

46 slots remaining

Real-time Synchronization

A unified command center for hosts and players. Monitor participant presence in real-time, adjust match parameters on the fly, and ensure every challenger is optimized for the battle ahead.

Live Participant Tracking

Dynamic Match Settings

Secure Room Protocols

Exit

18:20

Run

Submit

1. Two Sum

Easy

Array

Hash Table

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume each input has exactly one solution, and you may not use the same element twice. You can return the answer in any order.

Example 1

Input: nums = [2,7,11,15], target = 9

Output: [0,1]

// Because nums[0] + nums[1] = 9

Example 2

Input: nums = [3,2,4], target = 6

Output: [1,2]

// Because nums[1] + nums[2] = 6

Constraints

2 <= nums.length <= 104
-109 <= nums[i] <= 109
-109 <= target <= 109

JAVA

Code

Tests

Result

class Solution {
    public int[] twoSum(int[] nums, int target) {
        HashMap<Integer, Integer> map = new HashMap<>();

        for (int i = 0; i < nums.length; i++) {
            int complement = target - nums[i];
            if (map.containsKey(complement)) {
                return new int[] { map.get(complement), i };
            }
            map.put(nums[i], i);
        }
        return new int[] {};
    }
}

Optimized Performance

High-stakes coding without the latency. A dual-pane IDE synchronized with the arena server, featuring instant test feedback and a head-to-head submission tracker.

Sub-Millisecond Feedback

Dual-Pane Documentation

Cross-Player Status Sync

Alicia Brownaliciab

John Carterjohncarter

Ravi Vermaraviv

Rank	Player	Score	Verdict
1	John Carterjohncarter	120	Accepted
2	Alicia Brownaliciab	80	Accepted
3	Ravi Vermaraviv	50	System Error
4	Sharukh Khansharukhkhan	20	System Error

Post-Mortem Analytics

A technical breakdown of every competitive encounter. Analyze rankings, compare solution logic, and review granular performance metrics across the field.

Interactive Leaderboard

Animated Podium

In-Depth Verdict Reporting

Rust

Code

fn main() {
    let a = 25;
    let b = 17;
    
    println!("Calculating sum...");
    println!("Sum of {} + {} is: {}", a, b, a + b);
}

Input

Output

Success

24ms

Compiler Output

Calculating sum...

Sum of 25 + 17 is: 42

Compiler Playground

A high-performance sandbox where you can code and test logic in multiple languages. Execute your scripts instantly in a distraction-free environment.

Sub-second compilation

Standard input support

Live console feedback

Ready to enter the arena?

Join thousands of developers competing, growing, and proving their skills every day. Your rank is waiting.

Create Free Account Watch Live Battles

Free forever · No credit card required · Instant access

SlaveCode.

Your code is your master. Serve it well.

1. Two Sum

Everything you need to compete and grow.

1. Two Sum

Your journey, quantified in real-time.

XYZ XYZ

Network

Arena Records

Median of Two Sorted Arrays

Longest Palindrome

Two Sum

Median of Two Sorted Arrays

Longest Palindromic Substring

1,242submissions in the past one year

Define the Battlefield

Arena Lobby

Maximum Sum Path Challenge

Participants

Real-time Synchronization

1. Two Sum

Optimized Performance

Post-Mortem Analytics

Compiler Playground

Ready to enter the arena?

Your code is your master.
Serve it well.