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Codeforces: Export All Problems to PDF

Export all Codeforces contest problems to a printable PDF, styled like CPC contests.

  1. // ==UserScript==
  2. // @name         Codeforces: Export All Problems to PDF
  3. // @namespace    https://github.com/AnonMiraj
  4. // @author       ezzeldin
  5. // @license      GPL3
  6. // @description  Export all Codeforces contest problems to a printable PDF, styled like CPC contests.
  7. // @match        https://codeforces.com/group/*/contest/*
  8. // @match        https://codeforces.com/gym/*
  9. // @match        https://codeforces.com/contest/*
  10. // @grant        none
  11. // @esversion 11
  12. // @version 1.0
  13. // ==/UserScript==
  14.  
  15. (function () {
  16.     'use strict';
  17.  
  18.     if (!document.querySelector('table.datatable') && !document.querySelector('table.problems')) return;
  19.  
  20.     const container = document.querySelector('div[style*="text-align: right"] a[href*="/problems"]')?.parentElement;
  21.     if (!container) return;
  22.     const originalHTML = document.body.innerHTML;
  23.     const pdfLink = document.createElement('a');
  24.     pdfLink.textContent = '💾 Save All as PDF';
  25.     pdfLink.href = '#';
  26.     pdfLink.style.marginLeft = '15px';
  27.     pdfLink.style.color = '#0066cc';
  28.     pdfLink.style.textDecoration = 'none';
  29.     pdfLink.style.cursor = 'pointer';
  30.     container.appendChild(pdfLink);
  31.  
  32.     pdfLink.addEventListener('click', async (e) => {
  33.         e.preventDefault();
  34.         await exportPDF(pdfLink);
  35.     });
  36.  
  37.     async function exportPDF(link) {
  38.         const originalText = link.textContent;
  39.         link.style.pointerEvents = 'none';
  40.         link.textContent = 'Fetching…';
  41.  
  42.         const selectors = [
  43.             'table.datatable tr td.id a',
  44.             'table.datatable tr td.index a',
  45.             'table.problems tr td.id a',
  46.             'table.problems tr td.index a',
  47.             'table.datatable tr a[href*="/problem/"]',
  48.             'table.problems tr a[href*="/problem/"]'
  49.         ];
  50.  
  51.         const anchors = Array.from(document.querySelectorAll(selectors.join(',')));
  52.         const seen = new Set(), links = [];
  53.         anchors.forEach(a => {
  54.             if (!seen.has(a.href)) {
  55.                 seen.add(a.href);
  56.                 links.push(a.href);
  57.             }
  58.         });
  59.  
  60.         if (!links.length) return alert('No problem links found!');
  61.  
  62.         const problemsHTML = await Promise.all(
  63.             links.map(url => fetchProblem(url))
  64.         );
  65.  
  66.         document.body.innerHTML = problemsHTML
  67.             .map((html, i) => html || `<div><h2>Problem ${links[i].split('/').pop()} failed to load.</h2></div>`);
  68.  
  69.         document.querySelectorAll('.test-example-line-even, .test-example-line-odd').forEach(el => {
  70.             el.classList.remove('test-example-line-even', 'test-example-line-odd');
  71.         });
  72.  
  73.         document.querySelectorAll('.problem-statement').forEach((prob, i, arr) => {
  74.             const inputs = prob.querySelectorAll('.input');
  75.             const outputs = prob.querySelectorAll('.output');
  76.             if (inputs.length && outputs.length) {
  77.                 const table = document.createElement('table');
  78.                 table.className = 'samples-table';
  79.                 table.style.width = '100%';
  80.                 table.style.borderCollapse = 'collapse';
  81.                 table.style.marginBottom = '20px';
  82.  
  83.                 const header = table.insertRow();
  84.                 ['Standard Input', 'Standard Output'].forEach(text => {
  85.                     const th = document.createElement('th');
  86.                     th.textContent = text;
  87.                     th.style.border = '1px solid black';
  88.                     th.style.padding = '8px';
  89.                     th.style.textAlign = 'center';
  90.                     th.style.width = '50%';
  91.                     header.appendChild(th);
  92.                 });
  93.  
  94.                 for (let j = 0; j < Math.min(inputs.length, outputs.length); j++) {
  95.                     const row = table.insertRow();
  96.                     [inputs[j], outputs[j]].forEach(el => {
  97.                         const cell = row.insertCell();
  98.                         cell.style.border = '1px solid black';
  99.                         cell.style.padding = '8px';
  100.                         cell.style.verticalAlign = 'top';
  101.                         cell.appendChild(el);
  102.                     });
  103.                 }
  104.  
  105.                 const sample = prob.querySelector('.sample-tests') || prob.querySelector('.sample-test') || prob;
  106.                 sample?.parentNode?.insertBefore(table, sample.nextSibling);
  107.                 prob.querySelector('.sample-tests')?.remove();
  108.                 prob.querySelector('.sample-test')?.remove();
  109.             }
  110.  
  111.             if (i < arr.length - 1) {
  112.                 const pageBreak = document.createElement('div');
  113.                 pageBreak.style.pageBreakBefore = 'always';
  114.                 prob.parentNode.insertBefore(pageBreak, prob.nextSibling);
  115.             }
  116.         });
  117.  
  118.         const style = document.createElement('style');
  119.         style.textContent = `
  120.             .samples-table th, .samples-table td {
  121.                 border: 1px solid black;
  122.                 padding: 8px;
  123.                 vertical-align: top;
  124.                 text-align: left;
  125.             }
  126.             .samples-table pre {
  127.                 white-space: pre-wrap;
  128.                 word-wrap: break-word;
  129.                 font-size: 12px;
  130.                 margin: 0;
  131.             }
  132.             @media print {
  133.                 .samples-table th, .samples-table td {
  134.                     border: 1px solid black;
  135.                     padding: 8px;
  136.                 }
  137.             }
  138.         `;
  139.         document.head.appendChild(style);
  140.  
  141.         ['#MathJax_Message', '.status-bar', '#status', '.print-hide']
  142.             .forEach(sel => document.querySelectorAll(sel).forEach(el => el.style.display = 'none'));
  143.  
  144.         const finalize = () => setTimeout(() => {
  145.             document.getElementById('MathJax_Message')?.style.setProperty('display', 'none', 'important');
  146.             window.print();
  147.  
  148.             setTimeout(() => {
  149.                 document.body.innerHTML = originalHTML;
  150.                 link.style.pointerEvents = '';
  151.                 link.textContent = originalText;
  152.             }, 500);
  153.         }, 500);
  154.  
  155.         if (window.MathJax) {
  156.             try {
  157.                 if (MathJax.typesetPromise) {
  158.                     await MathJax.typesetPromise([document.body]);
  159.                     finalize();
  160.                 } else if (MathJax.Hub?.Queue) {
  161.                     MathJax.Hub.Queue(["Typeset", MathJax.Hub, document.body], finalize);
  162.                 } else finalize();
  163.             } catch (e) {
  164.                 finalize();
  165.             }
  166.         } else finalize();
  167.  
  168.         link.style.pointerEvents = '';
  169.         link.textContent = originalText;
  170.     }
  171.  
  172.     async function fetchProblem(url, retries = 2) {
  173.         try {
  174.             const res = await fetch(url);
  175.             const txt = await res.text();
  176.             const doc = new DOMParser().parseFromString(txt, 'text/html');
  177.             const prob = doc.querySelector('.problem-statement');
  178.             if (!prob) throw new Error('Missing problem-statement');
  179.  
  180.             prob.querySelectorAll('.input-output-copier').forEach(el => el.remove());
  181.  
  182.             const header = doc.querySelector('.header');
  183.             let title = 'Unknown Problem';
  184.             let inputFile = 'standard input';
  185.             let outputFile = 'standard output';
  186.             let timeLimit = 'N/A';
  187.             let memoryLimit = 'N/A';
  188.  
  189.             if (header) {
  190.                 title = header.querySelector('.title')?.textContent.trim() || title;
  191.                 inputFile = header.querySelector('.input-file')?.textContent.replace('input', '').trim() || inputFile;
  192.                 outputFile = header.querySelector('.output-file')?.textContent.replace('output', '').trim() || outputFile;
  193.                 timeLimit = header.querySelector('.time-limit')?.textContent.replace('time limit per test', '').trim() || timeLimit;
  194.                 memoryLimit = header.querySelector('.memory-limit')?.textContent.replace('memory limit per test', '').trim() || memoryLimit;
  195.                 header.remove();
  196.             }
  197.  
  198.             const h2 = document.createElement('h2');
  199.             h2.textContent = title;
  200.             h2.style.marginBottom = '0.2em';
  201.             h2.style.textAlign = 'left';
  202.             prob.insertBefore(h2, prob.firstChild);
  203.  
  204.             const metaDiv = document.createElement('div');
  205.             metaDiv.className = 'problem-metadata';
  206.             metaDiv.style.marginBottom = '1em';
  207. metaDiv.innerHTML = `
  208.     <pre style="font-family: monospace; margin-left: 20px; font-size: 14px;">
  209. Input file:\t${inputFile}
  210. Output file:\t${outputFile}
  211. Time limit:\t${timeLimit}
  212. Memory limit:\t${memoryLimit}
  213.     </pre>
  214. `;
  215.  
  216.  
  217.             prob.insertBefore(metaDiv, prob.firstChild.nextSibling);
  218.  
  219.             prob.querySelectorAll('.input .title, .output .title').forEach(el => el.remove());
  220.             return prob.outerHTML;
  221.  
  222.         } catch (err) {
  223.             if (retries > 0) {
  224.                 await new Promise(r => setTimeout(r, 400));
  225.                 return fetchProblem(url, retries - 1);
  226.             }
  227.             return null;
  228.         }
  229.     }
  230. })();
  231.  
  232.