Rings and Rods
0 likes • Nov 19, 2022
JavaScript
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const shuffle = ([...arr]) => {let m = arr.length;while (m) {const i = Math.floor(Math.random() * m--);[arr[m], arr[i]] = [arr[i], arr[m]];}return arr;};const foo = [1, 2, 3];shuffle(foo); // [2, 3, 1], foo = [1, 2, 3]
const longestPalindrome = (s) => {if(s.length === 1) return sconst odd = longestOddPalindrome(s)const even = longestEvenPalindrome(s)if(odd.length >= even.length) return oddif(even.length > odd.length) return even};const longestOddPalindrome = (s) => {let longest = 0let longestSubStr = ""for(let i = 1; i < s.length; i++) {let currentLongest = 1let currentLongestSubStr = ""let left = i - 1let right = i + 1while(left >= 0 && right < s.length) {const leftLetter = s[left]const rightLetter = s[right]left--right++if(leftLetter === rightLetter) {currentLongest += 2currentLongestSubStr = s.slice(left+1, right)} else break}if(currentLongest > longest) {if(currentLongestSubStr) longestSubStr = currentLongestSubStrelse longestSubStr = s[i]longest = currentLongest}}return longestSubStr}const longestEvenPalindrome = (s) => {let longest = 0let longestSubStr = ""for(let i = 0; i < s.length - 1; i++) {if(s[i] !== s[i+1]) continue;let currentLongest = 2let currentLongestSubStr = ""let left = i - 1let right = i + 2while(left >= 0 && right < s.length) {const leftLetter = s[left]const rightLetter = s[right]left--right++if(leftLetter === rightLetter) {currentLongest += 2currentLongestSubStr = s.slice(left+1, right)} else break}if(currentLongest > longest) {if(currentLongestSubStr) longestSubStr = currentLongestSubStrelse longestSubStr = s[i] + s[i+1]longest = currentLongest}}return longestSubStr}console.log(longestPalindrome("babad"))
questions = Array.from(document.querySelectorAll(".multiple-choice-question"));async function hackRadio(question){if(question.querySelector(".question-chevron").getAttribute("aria-label") == "Question completed") return;let answerChoices = question.querySelectorAll(".zb-radio-button");async function guess(answerChoice){answerChoice.querySelector("label").click();}let pause = 0;for(let answerChoice of answerChoices){setTimeout(()=>{guess(answerChoice)},pause); //No need to check given that it will record the correct answer anyways.pause += 1000;}}for(let question of questions){hackRadio(question);}questions = Array.from(document.querySelectorAll(".short-answer-question"));async function hackShortAnswer(question){if(question.querySelector(".question-chevron").getAttribute("aria-label") == "Question completed") return;question.querySelector("textarea").value = question.querySelector(".forfeit-answer").textContent;//question.querySelector(".check-button").click(); They are smart bastards}for(let question of questions){const showAnswerButton = question.querySelector(".show-answer-button");showAnswerButton.click();showAnswerButton.click();hackShortAnswer(question);}
const kMeans = (data, k = 1) => {const centroids = data.slice(0, k);const distances = Array.from({ length: data.length }, () =>Array.from({ length: k }, () => 0));const classes = Array.from({ length: data.length }, () => -1);let itr = true;while (itr) {itr = false;for (let d in data) {for (let c = 0; c < k; c++) {distances[d][c] = Math.hypot(...Object.keys(data[0]).map(key => data[d][key] - centroids[c][key]));}const m = distances[d].indexOf(Math.min(...distances[d]));if (classes[d] !== m) itr = true;classes[d] = m;}for (let c = 0; c < k; c++) {centroids[c] = Array.from({ length: data[0].length }, () => 0);const size = data.reduce((acc, _, d) => {if (classes[d] === c) {acc++;for (let i in data[0]) centroids[c][i] += data[d][i];}return acc;}, 0);for (let i in data[0]) {centroids[c][i] = parseFloat(Number(centroids[c][i] / size).toFixed(2));}}}return classes;};kMeans([[0, 0], [0, 1], [1, 3], [2, 0]], 2); // [0, 1, 1, 0]
var d = new Date();var d = new Date(milliseconds);var d = new Date(dateString);var d = new Date(year, month, day, hours, minutes, seconds, milliseconds);
const nums = [1, 2, 3];const strs = Array.from('est');nums.push(6);nums.push(4, 9);strs.unshift('t');nums.length; // 6nums[nums.length - 1]; // 9strs[0]; // 't'strs[2]; // 's'nums.slice(1, 3); // [2, 3]nums.map(n => n * 2); // [2, 4, 6, 12, 8, 18]nums.filter(n => n % 2 === 0); // [2, 6, 4]nums.reduce((a, n) => a + n, 0); // 25strs.reverse(); // ['t', 's', 'e', 't']strs.join(''); // 'test'const nums = new Set([1, 2, 3]);nums.add(4);nums.add(1);nums.add(5);nums.add(4);nums.size; // 5nums.has(4); // truenums.delete(4);nums.has(4); // false[...nums]; // [1, 2, 3, 5]nums.clear();nums.size; // 0const items = new Map([[1, { name: 'John' }],[2, { name: 'Mary' }]]);items.set(4, { name: 'Alan' });items.set(2, { name: 'Jeff' });items.size; // 3items.has(4); // trueitems.get(2); // { name: 'Jeff' }items.delete(2);items.size; // 2[...items.keys()]; // [1, 4][...items.values()]; // [{ name: 'John' }, { name: 'Alan' }]items.clear();items.size; // 0