洛谷一键跳转vjudge插件

支持洛谷一键跳转vjudge，只需在题目页面点击右键，选择“跳转vjudge”即可。

// ==UserScript==
// @name         洛谷一键跳转VJudge
// @namespace    http://tampermonkey.net/
// @version      1.0.0
// @description  支持洛谷所有题目跳转VJudge，修复CF带数字后缀的编号匹配
// @author       Tangyixao
// @match        https://www.luogu.com.cn/problem/CF*
// @match        https://www.luogu.com.cn/problem/SP*
// @match        https://www.luogu.com.cn/problem/AT*
// @match        https://www.luogu.com.cn/problem/UVA*
// @match        https://www.luogu.com.cn/problem/P*
// @grant        none
// ==/UserScript==

(function () {
  "use strict";

  function getVjudgeUrl() {
    const luoguUrl = window.location.href;
    const luoguPath = window.location.pathname;
    if (luoguPath.startsWith("/problem/P")) {
      const pMatch = luoguPath.match(/P(\d+)/);
      return pMatch
      ? `https://vjudge.net/problem/洛谷-P${pMatch[1]}` 
      : null;
    } else if (luoguPath.startsWith("/problem/AT_")) {
      const atMatch = luoguPath.match(/AT_(\w+)/);
      return atMatch
        ? `https://vjudge.net/problem/AtCoder-${atMatch[1]}`
        : null;
    } else if (luoguPath.startsWith("/problem/UVA")) {
      const uvaMatch = luoguPath.match(/UVA(\d+)/);
      return uvaMatch ? `https://vjudge.net/problem/UVA-${uvaMatch[1]}` : null;
    } else if (luoguPath.startsWith("/problem/CF")) {
      // 修复CF编号匹配
      const cfMatch = luoguPath.match(/CF(\d+[A-Za-z\d]*)/);
      return cfMatch
        ? `https://vjudge.net/problem/CodeForces-${cfMatch[1]}`
        : null;
    } else if (luoguPath.startsWith("/problem/SP")) {
      let spojId = null;
      const originalLink = document.querySelector(
        'a[href*="spoj.com/problems/"]',
      );
      if (originalLink) {
        spojId = originalLink.href.split("/problems/")[1].replace("/", "");
      } else {
        const pageText = document.body.innerText;
        const spojTextMatch = pageText.match(/SPOJ\s*[-\s:]([A-Za-z0-9_-]+)/i);
        spojId = spojTextMatch ? spojTextMatch[1].trim() : null;
      }
      return spojId ? `https://vjudge.net/problem/SPOJ-${spojId}` : null;
    }

    return null;
  }

  const copyBtn = Array.from(document.querySelectorAll("button")).find(
    (btn) => btn.innerText.trim() === "复制题目",
  );

  const vjudgeUrl = getVjudgeUrl();
  if (copyBtn && vjudgeUrl) {
    const jumpBtn = document.createElement("button");
    jumpBtn.innerText = "跳转VJudge";

    const copyStyles = window.getComputedStyle(copyBtn);
    [
      "backgroundColor",
      "color",
      "border",
      "borderRadius",
      "padding",
      "fontSize",
      "fontFamily",
      "cursor",
      "height",
      "lineHeight",
      "textAlign",
      "whiteSpace",
      "verticalAlign",
      "display",
      "marginTop",
      "marginBottom",
    ].forEach((styleProp) => {
      jumpBtn.style[styleProp] = copyStyles[styleProp];
    });

    jumpBtn.style.marginLeft = "5px";
    jumpBtn.style.minWidth = copyStyles.minWidth || "80px";

    jumpBtn.addEventListener("click", () => {
      window.open(vjudgeUrl, "_blank");
    });

    copyBtn.parentNode.insertBefore(jumpBtn, copyBtn.nextSibling);
  } else if (!vjudgeUrl) {
    const platform = luoguPath.match(/\/problem\/(\w+)/)[1].slice(0, 2);
    console.warn(
      `洛谷${platform}题目跳转VJudge：未找到有效题目标识符，请检查页面格式`,
    );
  }
})();