New updates to my CF duel app (chat + some changes)

Use it here: https://cf-1v1.vercel.app/dashboard

A small web app where you can do 1v1 duels with other CF users. You can also duel with friends and even do team battles using codes. Built mainly to make practice a bit more interactive.

I’ve been working on my duel app for a while and pushed a few updates recently.

Global chat

Added a simple global chat. Idea was just to make it easier to find people to duel instead of waiting or pinging randomly.

You can:

• talk to others
• ask for duels
• discuss problems (or anything tbh)

Not super fancy, but works fine for now.

Routing change

Earlier it was more like a single page setup, now moved to proper routing.

Main reason:

• in SPA, when users swipe back, the whole site was getting closed
• this was pretty annoying during usage

Now navigation behaves more normally.

Change username

You can now update your username. Small thing, but was annoying earlier.

Why I’m building this

Mostly because I wanted something where:

• starting a duel is quick
• people are actually active
• feels a bit more interactive than just sending requests

If you try it and something breaks / feels off, comment here. Also open to suggestions.

Team Battle Mode is Live on Codeforces Duel!

I’ve just launched a brand new Team Battle Mode on Codeforces Duel — where coding meets gaming!

Now you can team up with your friends and compete against other teams in a PUBG Mobile–style match lobby, making problem-solving more exciting than ever.

There are two fun ways to play:

First Solve Mode: Be the fastest — whoever solves first gets the points!

Total Solves Mode: Codeforces-style — solve as many as you can, and the team with the most points wins.

We’ve already hit 650+ users and seen 300+ duels take place — and it’s just getting started!

Watch the demo video here: watch here

Try it out: https://cf-1v1.vercel.app/

Codeforces 1v1 Duel — Challenge, Compete, and Climb the Leaderboard!

Hey everyone!

I’ve built something fun for all competitive programmers — a 1v1 Codeforces Duel platform where you can battle other coders in real time! Try it here: https://cfduel.vercel.app

What is Codeforces Duel? A place where you can duel with other users on real Codeforces problems. You can either:

Find a new opponent using the matchmaking system or Create a Duel ID and invite your friend

Key Features

Smart Matchmaking — automatically pairs you with players of similar rating

Custom Problem Filters — choose by tags, rating range, or even year of release

Live Timer — tracks the match in real time

Draw & Give Up options — just like real competitive battles

Leaderboard — track your duel rating and compete globally

Live chat — you can chat with opponent during match

Tech Behind the Platform Built using: React Node.js + WebSockets Codeforces API integration

Try it here: https://cfduel.vercel.app

Watch Demo here https://www.youtube.com/watch?v=eu9zR9WDju0

Whether you want to warm up before a contest or challenge your friends for fun, Codeforces Duel makes every problem a battle worth fighting.

Please share problems related to dijkstra algorithm and its modifications , please mention problem link and its rating

Share your favourite I will try solving them .

Its been 1year since I started my competitive programming journey and still I am in pupil. Can someone tell where am I going wrong and how should I improve myself.