codechef-io-copy.user.js

// ==UserScript==
// @name         Codechef IO Copy
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       nikhilksingh97
// @match        https://www.codechef.com/problems/*
// @grant        none
// ==/UserScript==


let styleSheet = `
.copyBtn {
    background-color: green;
    padding: 5px;
    font-size: 12px;
}
`;

let s = document.createElement('style');
s.type = "text/css";
s.innerHTML = styleSheet;
(document.head || document.documentElement).appendChild(s);

window.addEventListener('load', function() {
    'use strict';

    function copy(ele) {
        let temp = document.createElement('textarea');
        document.body.appendChild(temp);
        temp.value = ele.textContent;
        temp.select();
        document.execCommand('copy');
        temp.remove();
    }

    function addCopyBtn(ele) {
        let btn = document.createElement("button");
        btn.innerHTML = "Copy";
        btn.className = "copyBtn";
        btn.onclick = () => {
            copy(ele.lastChild);
        }

        ele.insertBefore(document.createElement('br'), ele.childNodes[0]);
        ele.insertBefore(btn, ele.childNodes[0]);
    }

    let preTags = document.getElementsByTagName("pre");

    console.log(preTags);

    for (let preTag of preTags) {
        addCopyBtn(preTag);
    }
});

Thanks

is it work for make spam?

lol

Wheare i can do userscrip?

Thank you. My great teacher.❤️❤️❤️❤️❤️ In my case, it doesn't work in Chrome browser. But it works in Edge browser. Maybe That my Chrome browser has installed too many plugins leads to this failure.

document.execCommand() method has been discarded. Maybe you should change the 33th line code to the code below

navigator.clipboard.writeText(temp.value); 

you can find solutions in this discussion、mdn document about clipboard and mdn document about execCommand.