在 VJudge 比赛题目页添加原题链接
// ==UserScript==
// @name VJudge 比赛显示原题链接
// @namespace https://vjudge.net/
// @version 0.1
// @description 在 VJudge 比赛题目页添加原题链接
// @match https://vjudge.net/contest/*
// @license MIT
// @grant none
// @run-at document-end
// ==/UserScript==
(function () {
'use strict';
const ANCHOR_CONTAINER_ID = 'vjudge-original-link-container';
const DEBOUNCE_MS = 120;
let titleObserver = null;
let bodyObserver = null;
let debounceTimer = null;
let lastDataJsonRaw = null;
function getProblemLetterFromHash() {
const m = location.hash.match(/#problem\/([^/?&]+)/);
return m ? m[1] : null;
}
function parseDataJsonSafely() {
const ta = document.querySelector('textarea[name="dataJson"]');
if (!ta) return null;
const raw = ta.value || ta.textContent || ta.innerText || '';
if (!raw) return null;
if (raw === lastDataJsonRaw) return JSON.parse(raw);
try {
const parsed = JSON.parse(raw);
lastDataJsonRaw = raw;
return parsed;
} catch (e) {
console.warn('vjudge-original-link: JSON parse failed', e);
return null;
}
}
function simpleObjHash(obj) {
try {
return String(JSON.stringify(obj));
} catch (e) {
return String(obj);
}
}
function ensureLinkContainerForProblem(problem, letter) {
const titleEl = document.getElementById('prob-title-contest');
if (!titleEl) return;
const existing = document.getElementById(ANCHOR_CONTAINER_ID);
const targetHash = problem ? simpleObjHash({ oj: problem.oj, pid: problem.pid, num: problem.num, title: problem.title }) : '';
const wantLetter = letter || '';
if (existing) {
if (existing.dataset.letter === wantLetter && existing.dataset.targetHash === targetHash) {
return; // nothing to do
}
existing.remove();
}
if (!problem) return;
const container = document.createElement('div');
container.id = ANCHOR_CONTAINER_ID;
container.style.marginTop = '6px';
container.style.fontSize = '14px';
container.style.lineHeight = '1.4';
container.dataset.letter = wantLetter;
container.dataset.targetHash = targetHash;
const oj = (problem.oj || '').toString().toLowerCase();
const title = problem.title || '';
let a = document.createElement('a');
a.style.textDecoration = 'none';
a.style.fontWeight = '500';
a.target = '_blank';
a.rel = 'noopener noreferrer';
if (oj.includes('luogu') || oj.includes('洛谷') || oj.includes('luogu.com')) {
const probNum = problem.probNum || problem.probID || problem.pid || null;
if (probNum) {
a.href = `https://www.luogu.com.cn/problem/${encodeURIComponent(probNum)}`;
a.textContent = `原题：洛谷 ${probNum}`;
} else {
a.removeAttribute('href');
a.textContent = '原题：暂不支持';
a.style.cursor = 'default';
}
} else if (oj.includes('qoj')) {
const q = encodeURIComponent(title || '');
a.href = `https://qoj.ac/problems?search=${q}`;
a.textContent = '原题：QOJ（点击搜索）';
} else if (oj.includes('codeforces')) {
const q = encodeURIComponent(title || '');
a.href = `https://www.luogu.com.cn/problem/list?keyword=${q}&type=CF&page=1`;
a.textContent = '原题：Codeforces（点击搜索）';
} else if (oj.includes('atcoder')) {
const probNum = problem.probNum || problem.probID || problem.pid || null;
const contestId = probNum.slice(0, probNum.lastIndexOf("_"));
a.href = `https://atcoder.jp/contests/${contestId}/tasks/${probNum}`;
a.textContent = `原题：AtCoder ${probNum}`;
} else if (oj.includes('uva')) {
const q = encodeURIComponent(title || '');
a.href = `https://www.luogu.com.cn/problem/list?keyword=${q}&type=UVA&page=1`;
a.textContent = '原题：UVA（点击搜索）';
} else if (oj.includes('universaloj')) {
const q = encodeURIComponent(title || '');
a.href = `https://uoj.ac/problems?search=${q}`;
a.textContent = '原题：UOJ（点击搜索）';
} else if (oj.includes('libreoj')) {
const q = encodeURIComponent(title || '');
a.href = `https://loj.ac/p?keyword=${q}`;
a.textContent = '原题：LOJ（点击搜索）';
} else {
a.removeAttribute('href');
a.textContent = `原题：来自 ${oj}，暂不支持查找`;
a.style.cursor = 'default';
}
container.appendChild(a);
try {
titleEl.appendChild(container);
} catch (e) {
console.warn('vjudge-original-link: insert failed', e);
}
}
// 主要更新逻辑（防抖）
function handleUpdate() {
clearTimeout(debounceTimer);
debounceTimer = setTimeout(() => {
try {
const letter = getProblemLetterFromHash();
if (!letter) {
const ex = document.getElementById(ANCHOR_CONTAINER_ID);
if (ex) ex.remove();
return;
}
const data = parseDataJsonSafely();
if (!data || !Array.isArray(data.problems)) {
const ex2 = document.getElementById(ANCHOR_CONTAINER_ID);
if (ex2) ex2.remove();
return;
}
const target = data.problems.find(p => {
if (!p) return false;
if (p.num && String(p.num).toUpperCase() === String(letter).toUpperCase()) return true;
if (p.num && String(p.num).toUpperCase().includes(String(letter).toUpperCase())) return true;
return false;
}) || null;
ensureLinkContainerForProblem(target, letter);
} catch (err) {
console.error('vjudge-original-link: handleUpdate error', err);
}
}, DEBOUNCE_MS);
}
function startTitleObserver() {
stopTitleObserver();
const titleEl = document.getElementById('prob-title-contest');
if (!titleEl) return;
titleObserver = new MutationObserver((mutations) => {
for (const m of mutations) {
if (m.addedNodes) {
for (const n of m.addedNodes) {
if (n && n.id === ANCHOR_CONTAINER_ID) {
return;
}
if (n && n.querySelector && n.querySelector(`#${ANCHOR_CONTAINER_ID}`)) {
return;
}
}
}
}
handleUpdate();
});
titleObserver.observe(titleEl, { childList: true, subtree: true, characterData: true });
}
function stopTitleObserver() {
if (titleObserver) {
try { titleObserver.disconnect(); } catch (e) {}
titleObserver = null;
}
}
function startBodyObserver() {
if (bodyObserver) return;
bodyObserver = new MutationObserver((mutations) => {
for (const m of mutations) {
if (m.addedNodes) {
for (const n of m.addedNodes) {
if (n && n.querySelector && n.querySelector('#prob-title-contest')) {
setTimeout(() => {
startTitleObserver();
handleUpdate();
}, 20);
return;
}
if (n && n.id === 'prob-title-contest') {
setTimeout(() => {
startTitleObserver();
handleUpdate();
}, 20);
return;
}
}
}
}
});
bodyObserver.observe(document.body, { childList: true, subtree: true });
}
function stopBodyObserver() {
if (bodyObserver) {
try { bodyObserver.disconnect(); } catch (e) {}
bodyObserver = null;
}
}
function tryInit(retries = 10) {
const titleEl = document.getElementById('prob-title-contest');
if (titleEl) {
startTitleObserver();
startBodyObserver();
handleUpdate();
} else if (retries > 0) {
setTimeout(() => tryInit(retries - 1), 300);
} else {
startBodyObserver();
}
}
window.addEventListener('hashchange', () => {
setTimeout(handleUpdate, 80);
});
// run
tryInit();
window.__vjudge_original_link_cleanup = function () {
stopTitleObserver();
stopBodyObserver();
const ex = document.getElementById(ANCHOR_CONTAINER_ID);
if (ex) ex.remove();
console.info('vjudge-original-link: cleaned up');
};
})();