AtCoder のコンテストページにおいて、問題タブをホバーするとドロップダウンリストを表示するようにします。
// ==UserScript==
// @name AtCoder Dropdown Tasks
// @namespace https://atcoder.jp/
// @version 2026-04-05
// @description AtCoder のコンテストページにおいて、問題タブをホバーするとドロップダウンリストを表示するようにします。
// @author magurofly
// @match https://atcoder.jp/contests/*
// @icon https://www.google.com/s2/favicons?sz=64&domain=atcoder.jp
// @grant unsafeWindow
// @license CC0-1.0 Universal
// ==/UserScript==
(async function() {
'use strict';
if (typeof unsafeWindow.contestScreenName !== "string") return;
const contestScreenName = unsafeWindow.contestScreenName;
const navTabsBox = document.querySelector("#contest-nav-tabs").getBoundingClientRect()
const styleSheet = new CSSStyleSheet();
styleSheet.replace(`
.atcoder-dropdown-tasks:hover .dropdown-menu {
display: block;
overflow: auto;
max-height: calc(100vh - ${navTabsBox.top}px - ${navTabsBox.height}px - 2em);
}
.atcoder-dropdown-task li {
font-family: monospace;
}
.atcoder-dropdown-tasks li.current-task {
background-color: #eeeeee;
font-weight: bold;
}
.atcoder-dropdown-tasks li.current-task a {
font-weight: bold;
padding-left: calc(18px - 1em);
}
.atcoder-dropdown-tasks li.current-task a::before {
content: "\u25b6";
padding-right: 2px;
}
`);
document.adoptedStyleSheets.push(styleSheet);
const tasksDropdown = unsafeWindow.document.querySelector("#contest-nav-tabs > ul > li:nth-child(2)");
tasksDropdown.classList.add("atcoder-dropdown-tasks");
const tasksDropdownButton = tasksDropdown.querySelector("a");
tasksDropdownButton.insertAdjacentHTML("beforeend", `<span class="caret"></span>`);
const tasksDropdownContents = document.createElement("ul");
tasksDropdownContents.className = "dropdown-menu";
tasksDropdown.appendChild(tasksDropdownContents);
let currentTaskURL = null;
let matchResult;
if (matchResult = /^\/contests\/[^\/]+\/tasks\/[^\/?]+/.exec(location.pathname)) {
currentTaskURL = location.origin + matchResult[0];
} else if (/^\/contests\/[^\/]+\/submissions\/\d+/.test(location.pathname)) {
const link = document.querySelector("#main-container > div.row > div:nth-child(2) > div:nth-child(8) > table > tbody > tr:nth-child(2) > td > a");
currentTaskURL = link.href;
} else if (/^\/contests\/[^\/]+\/editorial\/\d+/.test(location.pathname)) {
const link = document.querySelector("#main-container > div.row > div:nth-child(2) > h2 > a");
currentTaskURL = link.href;
}
let currentLink = null;
const tasksHTML = await (await fetch(`/contests/${contestScreenName}/tasks`)).text();
const tasksDoc = new DOMParser().parseFromString(tasksHTML, "text/html");
for (const row of tasksDoc.querySelectorAll("#main-container > div.row > div:nth-child(2) > div.panel.panel-default.table-responsive > table > tbody > tr")) {
const taskNum = row.cells[0].textContent;
const taskName = row.cells[1].textContent;
const taskURL = row.cells[0].children[0].href;
const link = document.createElement("a");
link.href = taskURL;
link.textContent = `${taskNum} - ${taskName}`;
const li = document.createElement("li");
li.appendChild(link);
if (taskURL == currentTaskURL) {
li.classList.add("current-task");
currentLink = link;
}
tasksDropdownContents.appendChild(li);
}
if (currentLink) {
tasksDropdown.addEventListener("mouseenter", currentLink.scrollIntoView.bind(currentLink, { block: "nearest" }), { once: true });
}
})();