在 CodeChef、QOJ、Codeforces 题目页提供跳转到对应 VJudge/Luogu 题目的按钮（可切换为自动跳转）
// ==UserScript==
// @name CodeChef/QOJ/Codeforces → VJudge/Luogu Redirect
// @namespace http://tampermonkey.net/
// @version 1.4
// @description 在 CodeChef、QOJ、Codeforces 题目页提供跳转到对应 VJudge/Luogu 题目的按钮（可切换为自动跳转）
// @author znzryb
// @match https://www.codechef.com/problems/*
// @match https://qoj.ac/problem/*
// @match https://qoj.ac/contest/*/problem/*
// @match https://codeforces.com/contest/*/problem/*
// @match https://codeforces.com/problemset/problem/*/*
// @match https://codeforces.com/gym/*/problem/*
// @grant none
// @license GPL-3.0
// @run-at document-idle
// ==/UserScript==
(function () {
'use strict';
/** 工具函数：创建并挂载按钮（避免重复） */
function createJumpButton(targetUrl, label = 'Jump to VJudge', buttonId = 'vj-redirect-btn', topOffset = '100px') {
if (!targetUrl) return;
if (document.getElementById(buttonId)) return;
const btn = document.createElement('button');
btn.id = buttonId;
btn.textContent = label;
Object.assign(btn.style, {
position: 'fixed',
top: topOffset,
right: '20px',
padding: '10px 15px',
backgroundColor: '#28a745',
color: '#fff',
border: 'none',
borderRadius: '6px',
cursor: 'pointer',
fontSize: '14px',
zIndex: 10000,
boxShadow: '0 2px 10px rgba(0,0,0,0.15)',
});
btn.onmouseenter = () => (btn.style.opacity = '0.9');
btn.onmouseleave = () => (btn.style.opacity = '1');
btn.addEventListener('click', () => {
window.open(targetUrl, '_blank');
});
document.body.appendChild(btn);
}
/** 检测当前是否为单独的 Div2 比赛 */
function isStandaloneDivision2() {
// 获取比赛标题元素
const contestNameElement = document.querySelector('.contest-name') ||
document.querySelector('#sidebar .rtable a');
if (!contestNameElement) return false;
const contestName = contestNameElement.textContent.trim();
// 检查是否包含 "Div. 2" 但不包含 "+"（排除联合比赛）
if (contestName.includes('Div. 2') && !contestName.includes('+')) {
// 排除 Div. 3、Div. 4 等
if (contestName.includes('Div. 3') || contestName.includes('Div. 4')) {
return false;
}
return true;
}
return false;
}
/** 提取比赛名称的关键标识（如 "Round 1069"） */
function extractRoundIdentifier(contestName) {
// 尝试提取 "Round XXX" 或 "Educational Codeforces Round XXX" 等
const roundMatch = contestName.match(/Round\s+(\d+)/i);
if (roundMatch) {
return `Round ${roundMatch[1]}`;
}
// 其他可能的格式
const eduMatch = contestName.match(/Educational.*?Round\s+(\d+)/i);
if (eduMatch) {
return `Educational Round ${eduMatch[1]}`;
}
return null;
}
/** 验证 Div1 比赛是否存在并比较比赛名称 */
async function verifyDiv1Contest(div1ContestId, div2ContestName) {
try {
// 获取 Div1 比赛页面
const response = await fetch(`https://codeforces.com/contest/${div1ContestId}`);
if (!response.ok) return false;
const html = await response.text();
const parser = new DOMParser();
const doc = parser.parseFromString(html, 'text/html');
// 提取 Div1 比赛名称
const div1NameElement = doc.querySelector('.contest-name') ||
doc.querySelector('#sidebar .rtable a');
if (!div1NameElement) return false;
const div1ContestName = div1NameElement.textContent.trim();
// 比较比赛名称的关键标识
const div2Identifier = extractRoundIdentifier(div2ContestName);
const div1Identifier = extractRoundIdentifier(div1ContestName);
if (div2Identifier && div1Identifier && div2Identifier === div1Identifier) {
return true;
}
return false;
} catch (error) {
console.error('验证 Div1 比赛失败:', error);
return false;
}
}
/** 获取 Div1 比赛的题目列表 */
async function fetchDiv1Problems(div1ContestId) {
try {
// 方法1：使用 Codeforces API
const apiUrl = `https://codeforces.com/api/contest.standings?contestId=${div1ContestId}&from=1&count=1`;
const response = await fetch(apiUrl);
if (!response.ok) {
throw new Error('API 请求失败');
}
const data = await response.json();
if (data.status === 'OK' && data.result && data.result.problems) {
// 返回题目数组，每个题目包含 index 和 name
return data.result.problems.map(problem => ({
index: problem.index,
name: problem.name
}));
}
throw new Error('API 返回数据格式错误');
} catch (error) {
console.error('获取 Div1 题目列表失败:', error);
// 方法2：解析比赛页面（备用方案）
try {
const response = await fetch(`https://codeforces.com/contest/${div1ContestId}`);
const html = await response.text();
const parser = new DOMParser();
const doc = parser.parseFromString(html, 'text/html');
const problems = [];
const problemLinks = doc.querySelectorAll('.problems td.id a');
problemLinks.forEach(link => {
const index = link.textContent.trim();
const row = link.closest('tr');
const nameElement = row.querySelector('td:nth-child(2) a');
if (nameElement) {
problems.push({
index: index,
name: nameElement.textContent.trim()
});
}
});
return problems;
} catch (fallbackError) {
console.error('备用方案也失败:', fallbackError);
return [];
}
}
}
/** 查找匹配的 Div1 题目 */
function findMatchingDiv1Problem(currentProblemName, div1Problems) {
// 清理题目名称（移除题号前缀）
const cleanName = (name) => {
return name.replace(/^[A-Z]\d?\.\s*/, '').trim();
};
const cleanCurrentName = cleanName(currentProblemName);
for (const problem of div1Problems) {
const cleanDiv1Name = cleanName(problem.name);
if (cleanCurrentName === cleanDiv1Name) {
return problem.index;
}
}
return null;
}
/** 解析当前站点并生成对应的 VJudge URL */
const { host, pathname } = window.location;
// —— CodeChef ————————————————————————————————————————————————
// URL 一般为 /problems/ABCDEF 或 /problems/ABCDEF?tab=statement
if (host.includes('codechef.com')) {
const parts = pathname.split('/').filter(Boolean); // ['problems','ABCDEF']
let problemCode = parts[1] || ''; // 索引 1 为题号
// 去掉可能存在的查询串（通常问题代码不含 ?，此处保险处理）
problemCode = problemCode.split('?')[0];
if (!problemCode) return;
const vjudgeUrl = `https://vjudge.net/problem/CodeChef-${problemCode}`;
// === AUTO REDIRECT（可选）===
// 如果需要自动跳转，取消下面一行注释：
// window.location.href = vjudgeUrl;
// 否则创建按钮
createJumpButton(vjudgeUrl, 'Jump to VJudge');
return;
}
// —— QOJ ————————————————————————————————————————————————
// 支持：
// /problem/14548
// /contest/2521/problem/14501
if (host === 'qoj.ac') {
let qojPid = '';
// 形式1：/problem/:pid
let m = pathname.match(/^\/problem\/(\d+)(?:\/)?$/);
if (m) {
qojPid = m[1];
} else {
// 形式2：/contest/:cid/problem/:pid
m = pathname.match(/^\/contest\/(\d+)\/problem\/(\d+)(?:\/)?$/);
if (m) {
qojPid = m[2];
}
}
if (!qojPid) return;
const vjudgeUrl = `https://vjudge.net/problem/QOJ-${qojPid}`;
// === AUTO REDIRECT（可选）===
// 如果需要自动跳转，取消下面一行注释：
// window.location.href = vjudgeUrl;
createJumpButton(vjudgeUrl, 'Jump to VJudge');
return;
}
// —— Codeforces ————————————————————————————————————————————————
// 支持：
// /contest/2120/problem/D
// /problemset/problem/2120/D
// /gym/105578/problem/E
if (host === 'codeforces.com') {
let contestId = '';
let problemIndex = '';
let isGym = false;
let isContest = false;
// 形式1：/contest/:cid/problem/:index
let m = pathname.match(/^\/contest\/(\d+)\/problem\/([A-Z]\d?)(?:\/)?$/i);
if (m) {
contestId = m[1];
problemIndex = m[2];
isContest = true;
} else {
// 形式2：/problemset/problem/:cid/:index
m = pathname.match(/^\/problemset\/problem\/(\d+)\/([A-Z]\d?)(?:\/)?$/i);
if (m) {
contestId = m[1];
problemIndex = m[2];
} else {
// 形式3：/gym/:cid/problem/:index
m = pathname.match(/^\/gym\/(\d+)\/problem\/([A-Z]\d?)(?:\/)?$/i);
if (m) {
contestId = m[1];
problemIndex = m[2];
isGym = true;
}
}
}
if (!contestId || !problemIndex) return;
// 处理 Div2 -> Div1 转换（仅针对 contest 页面）
if (isContest && isStandaloneDivision2()) {
(async () => {
try {
// 获取当前题目名称
const problemTitleElement = document.querySelector('.problem-statement .title') ||
document.querySelector('.header .title');
if (!problemTitleElement) {
throw new Error('无法获取题目标题');
}
const currentProblemName = problemTitleElement.textContent.trim();
// 获取当前比赛名称
const contestNameElement = document.querySelector('.contest-name') ||
document.querySelector('#sidebar .rtable a');
if (!contestNameElement) {
throw new Error('无法获取比赛名称');
}
const div2ContestName = contestNameElement.textContent.trim();
// 计算 Div1 contest ID
const div1ContestId = parseInt(contestId) - 1;
// 验证 Div1 比赛是否存在且相关
const isRelated = await verifyDiv1Contest(div1ContestId, div2ContestName);
if (isRelated) {
// 获取 Div1 题目列表
const div1Problems = await fetchDiv1Problems(div1ContestId);
if (div1Problems.length > 0) {
// 查找匹配的题目
const matchedIndex = findMatchingDiv1Problem(currentProblemName, div1Problems);
if (matchedIndex) {
// 找到匹配的 Div1 题目，使用 Div1 链接
console.log(`找到对应的 Div1 题目: ${div1ContestId}${matchedIndex}`);
const luoguUrl = `https://www.luogu.com.cn/problem/CF${div1ContestId}${matchedIndex}`;
const vjudgeUrl = `https://vjudge.net/problem/CodeForces-${contestId}${problemIndex}`;
createJumpButton(luoguUrl, 'Jump to Luogu', 'luogu-redirect-btn', '100px');
createJumpButton(vjudgeUrl, 'Jump to VJudge', 'vj-redirect-btn', '150px');
return;
}
}
}
// 如果没有找到对应的 Div1 题目，使用原始链接
console.log('未找到对应的 Div1 题目，使用原始链接');
throw new Error('使用原始链接');
} catch (error) {
console.log('Div2->Div1 转换失败，使用原始链接:', error.message);
// 降级：使用原始的 Div2 链接
const luoguUrl = `https://www.luogu.com.cn/problem/CF${contestId}${problemIndex}`;
const vjudgeUrl = `https://vjudge.net/problem/CodeForces-${contestId}${problemIndex}`;
createJumpButton(luoguUrl, 'Jump to Luogu', 'luogu-redirect-btn', '100px');
createJumpButton(vjudgeUrl, 'Jump to VJudge', 'vj-redirect-btn', '150px');
}
})();
return;
}
// 普通情况：直接生成跳转链接
// Gym 题目在 VJudge 上格式为 Gym-105578E（无分隔符）
// 普通题目格式为 CodeForces-2120D
const luoguUrl = `https://www.luogu.com.cn/problem/CF${contestId}${problemIndex}`;
const vjudgeUrl = isGym
? `https://vjudge.net/problem/Gym-${contestId}${problemIndex}`
: `https://vjudge.net/problem/CodeForces-${contestId}${problemIndex}`;
// === AUTO REDIRECT（可选）===
// 如果需要自动跳转到 Luogu，取消下面一行注释：
// window.location.href = luoguUrl;
// 如果需要自动跳转到 VJudge，取消下面一行注释：
// window.location.href = vjudgeUrl;
// 创建两个按钮
createJumpButton(luoguUrl, 'Jump to Luogu', 'luogu-redirect-btn', '100px');
createJumpButton(vjudgeUrl, 'Jump to VJudge', 'vj-redirect-btn', '150px');
return;
}
// 其他域名不处理
})();