Automatically fetch answers for tasks
// ==UserScript==
// @name 头歌自动尝试正确答案
// @match *://*.educoder.net/tasks/*
// @namespace http://tampermonkey.net/
// @version 1.0
// @description Automatically fetch answers for tasks
// @author Owwk
// @grant none
// ==/UserScript==
(function () {
'use strict';
// 定义答案的所有可能组合
const answers = [];
const delayMs = 1;
const isDelay = false;
function fillAnswers(maxChar) {
const options = [];
for (let i = 'A'.charCodeAt(0); i <= maxChar.charCodeAt(0); i++) {
options.push(String.fromCharCode(i));
}
for (let i = 1; i <= options.length; i++) {
combinations(options, i).forEach(c => answers.push(c.join('')));
}
console.info("答案组合", answers)
}
function combinations(arr, k) {
const result = [];
const combination = (start, prefix) => {
if (prefix.length === k) {
result.push(prefix);
return;
}
for (let i = start; i < arr.length; i++) {
combination(i + 1, prefix.concat(arr[i]));
}
};
combination(0, []);
return result;
}
// 每秒获取一次目标元素，超时时间为5秒
const interval = setInterval(() => {
const target = document.querySelector('#task-left-panel > div.task-header > span');
if (target) {
clearInterval(interval);
insertButton(target);
}
}, 1000);
setTimeout(() => clearInterval(interval), 5000);
function insertButton(target) {
const button = document.createElement('button');
button.textContent = 'Fetch Answer';
button.style.marginRight = '10px';
target.parentElement.insertBefore(button, target);
button.addEventListener('click', () => {
const userInput = prompt('请输入fetch字符串:');
if (userInput) {
try {
const { url, options } = parseFetchString(userInput);
attemptAllCombinations(url, options);
} catch (e) {
alert('无效的fetch字符串');
}
}
});
}
function parseFetchString(fetchString) {
const urlMatch = fetchString.match(/fetch\("([^"]+)"/);
const optionsMatch = fetchString.match(/,\s*({[\s\S]*})\s*\)\s*;/);
if (!urlMatch || !optionsMatch) {
throw new Error('无法解析fetch字符串');
}
const url = urlMatch[1];
const options = JSON.parse(optionsMatch[1]);
return { url, options };
}
async function attemptAllCombinations(url, options) {
// 解析 options.body 获取答案数组的长度
let bodyObj = JSON.parse(options.body);
const answerLength = bodyObj.answer.length;
let maxChar = 'A';
// 解析最大Char
bodyObj.answer.forEach((val, index) => {
if (val > maxChar) {
maxChar = val;
}
});
fillAnswers(maxChar);
// 初始化 correctAnswers 数组，假设所有题目都是错误的
let correctAnswers = Array(answerLength).fill(false);
let num = 0;
for (let answer of answers) {
num++;
bodyObj = modifyRequestBody(bodyObj, answer, correctAnswers);
const newRequestOptions = { ...options, body: JSON.stringify(bodyObj) };
const response = await sendRequest(url, newRequestOptions);
console.info("尝试", num, bodyObj.answer)
// 更新 correctAnswers 数组，标记已经正确的题目
correctAnswers = updateCorrectAnswers(correctAnswers, response);
console.info("结果", num, correctAnswers)
if (isAllCorrect(response)) {
alert('找到正确答案: ' + getAnswer(response).join(', '));
break
}
if (isDelay) await delay(delayMs);
}
}
function updateCorrectAnswers(correctAnswers, response) {
// 遍历 response 中的 test_sets，更新 correctAnswers
response.test_sets.forEach((test, index) => {
if (test.result) {
correctAnswers[index] = true;
}
});
return correctAnswers;
}
function modifyRequestBody(body, answer, correctAnswers) {
const bodyObj = body;
// 仅在对应位置没有正确答案时才修改答案数组
for (let i = 0; i < bodyObj.answer.length; i++) {
if (!correctAnswers[i]) {
bodyObj.answer[i] = answer;
}
}
return bodyObj
}
function sendRequest(url, options) {
Object.keys(options.headers).forEach(header => {
if (header.startsWith('x-edu-')) {
delete options.headers[header];
}
});
return fetch(url, options)
.then(response => response.json())
.catch(error => console.error('Error:', error));
}
function isAllCorrect(response) {
return response.test_sets.every(test => test.result);
}
function getAnswer(response) {
return response.test_sets.map(val => val.actual_output)
}
function delay(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
})();