tampermonkey script for automatically filling codeforces problem identifier

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Hello Codeforces community,

I noticed that when opening a problem from the problemset page, then going to the submit page, you usually have to manually type the problem identifier each time unless you entered through the contest page, so I made a Tampermonkey script that parses the current problem URL, stores the identifier, and automatically fills it into the submit form. :D (Note that you do need TamperMonkey installed, link to that here.$$$\newline$$$

TamperMonkey Code

// ==UserScript==
// @name         Codeforces Problem Submit Helper
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Fetches the current Codeforces URL, and parses it for the problem identifier and automatically puts it in the field that asks for it.
// @author       SirRogue
// @match        *://codeforces.com/*
// @match        *://www.codeforces.com/*
// @run-at       document-idle
// ==/UserScript==
(function(){
    'use strict';
    const currenturl=window.location.href;
    function extractproblemidentifier(urlstr){
        if(!urlstr){
            return null;
        }
        const problemset=/problemset\/problem\/(\d+)\/([A-Za-z0-9]+)/i;
        const match=urlstr.match(problemset);
        if(match){
            return match[1]+match[2].toUpperCase();
        }
        return null;
    }
    const problemidentifier=extractproblemidentifier(currenturl);
    if(problemidentifier){
        localStorage.setItem('problemidentifier',problemidentifier);
        return;
    }
    if(/\/problemset\/submit\b/.test(currenturl)){
        const savedproblemidentifier=localStorage.getItem('problemidentifier');
        if(!savedproblemidentifier){
            return;
        }
        const input=
            document.querySelector('input[name="submittedProblemCode"]')||
            document.querySelector('input[name="submittedProblemIndex"]')||
            document.querySelector('input[type="text"]');
        if(input){
            input.value=savedproblemidentifier;
            input.dispatchEvent(new Event('input',{bubbles:true}));
            input.dispatchEvent(new Event('change',{bubbles:true}));
        }
    }
})();

Comments (6)

Write comment?

rishivarun_007

5 months ago, hide # |

+10

Thanks!! Very Helpful.

→ Reply

JJCUBER

Alternatively, you can easily get to the contest version of the page by clicking the "Codeforces Round $$$n$$$" text in the top-right corner of the problem you are on, after which problems, submit, and status buttons will behave "nicely."

SirRogue

5 months ago, hide # ^ |

I know you could do that, but it's for people who just solve off the problemset and I saw people complaining about the fact they had to add the problem identifier, so I figured this would help people.

Yeah I was mostly just providing it as an alternative for people who aren't interested in installing extensions. I remember it taking me a long time to realize that clicking that text would fix things.

wuyuetong

Oh, thank you! That’s been a great help to me.

+16

You are welcome, glad it could help :D

SirRogue's blog