Auto Select CF Language

Auto selects the language based on file extension, when you upload a file

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Auto Select CF Language
// @namespace    http://tampermonkey.net/
// @version      0.2.1
// @description  Auto selects the language based on file extension, when you upload a file
// @author       Mushfiqur Rahman Talha
// @match        *codeforces.com/contest/*/problem/*
// @match        *codeforces.com/problemset/problem/*
// @match        *mirror.codeforces.com/contest/*/problem/*
// @match        *mirror.codeforces.com/problemset/problem/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=codeforces.com
// @grant        none
// @license      Apache-2.0
// ==/UserScript==

(function() {
    'use strict';

    /*
    Language Support:
     - GNU GCC C11 5.1.0
     - GNU G++23 14.2 (64 bit, msys2)
     - C# 10, .NET SDK 6.0
     - D DMD32 v2.105.0
     - Go 1.22.2
     - Java 21 64bit
     - Kotlin 1.9.21
     - OCaml 4.02.1
     - PHP 8.1.7
     - PyPy 3.10 (7.3.15, 64bit)
     - Ruby 3.2.2
     - Rust 1.75.0 (2021)
     - Node.js 15.8.0 (64bit)
    */
    const fileInput = document.querySelector("input[name=sourceFile]");

    const languageId = {
        // C++
        "cpp" : 91,
        "cc"  : 91,
        "cxx" : 91,
        "c++" : 91,
        "cp"  : 91,
        
        // C
        "c"   : 43,
        
        // Java
        "java": 87,
        
        // Python
        "py"  : 70,
        "pyw" : 70,
        "py3" : 70,
        
        // C#
        "cs"  : 79,
        
        // JavaScript
        "js"  : 55,
        "mjs" : 55,
        
        // D
        "d"   : 28,
        
        // Go
        "go"  : 32,
        
        // Kotlin
        "kt"  : 88,
        "kts" : 88,
        
        // OCaml
        "ml"  : 19,
        "mli" : 19,
        
        // PHP
        "php" : 6,
        "php3": 6,
        "php4": 6,
        "php5": 6,
        "phtml": 6,
        
        // Ruby
        "rb"  : 67,
        "rbw" : 67,
        
        // Rust
        "rs"  : 75,
    };

    fileInput.addEventListener("change", event => {
        const file = event.target.files[0];
        if (!file) return;
        const ext = file.name.split('.').pop().toLowerCase();
        let optionValue = languageId[ext] || 91; // Default to C++ if extension not found

        document.querySelectorAll("option").forEach(element => element.removeAttribute("selected"));
        document.querySelector(`option[value='${optionValue}']`).setAttribute("selected", "selected");
    });
})();