Loading...
More JavaScript Posts
const gcd = (...arr) => {const _gcd = (x, y) => (!y ? x : gcd(y, x % y));return [...arr].reduce((a, b) => _gcd(a, b));};gcd(8, 36); // 4gcd(...[12, 8, 32]); // 4
class TreeNode {constructor(key, value = key, parent = null) {this.key = key;this.value = value;this.parent = parent;this.children = [];}get isLeaf() {return this.children.length === 0;}get hasChildren() {return !this.isLeaf;}}class Tree {constructor(key, value = key) {this.root = new TreeNode(key, value);}*preOrderTraversal(node = this.root) {yield node;if (node.children.length) {for (let child of node.children) {yield* this.preOrderTraversal(child);}}}*postOrderTraversal(node = this.root) {if (node.children.length) {for (let child of node.children) {yield* this.postOrderTraversal(child);}}yield node;}insert(parentNodeKey, key, value = key) {for (let node of this.preOrderTraversal()) {if (node.key === parentNodeKey) {node.children.push(new TreeNode(key, value, node));return true;}}return false;}remove(key) {for (let node of this.preOrderTraversal()) {const filtered = node.children.filter(c => c.key !== key);if (filtered.length !== node.children.length) {node.children = filtered;return true;}}return false;}find(key) {for (let node of this.preOrderTraversal()) {if (node.key === key) return node;}return undefined;}}const tree = new Tree(1, 'AB');tree.insert(1, 11, 'AC');tree.insert(1, 12, 'BC');tree.insert(12, 121, 'BG');[...tree.preOrderTraversal()].map(x => x.value);// ['AB', 'AC', 'BC', 'BCG']tree.root.value; // 'AB'tree.root.hasChildren; // truetree.find(12).isLeaf; // falsetree.find(121).isLeaf; // truetree.find(121).parent.value; // 'BC'tree.remove(12);[...tree.postOrderTraversal()].map(x => x.value);// ['AC', 'AB']
import React, { useState } from 'react' import Welcome from '../components/Welcome' function About() { const [showWelcome, setShowWelcome] = useState(false) return ( <div> {showWelcome ? <Welcome /> : null} </div> <div> {showWelcome && <Welcome /> } </div> ) } export default App
// There are n rings and each ring is either red, green, or blue. The rings are distributed across ten rods labeled from 0 to 9.// You are given a string rings of length 2n that describes the n rings that are placed onto the rods. Every two characters in rings forms a color-position pair that is used to describe each ring where:// The first character of the ith pair denotes the ith ring's color ('R', 'G', 'B').// The second character of the ith pair denotes the rod that the ith ring is placed on ('0' to '9').// For example, "R3G2B1" describes n == 3 rings: a red ring placed onto the rod labeled 3, a green ring placed onto the rod labeled 2, and a blue ring placed onto the rod labeled 1.// Return the number of rods that have all three colors of rings on them.let rings = "B0B6G0R6R0R6G9";var countPoints = function(rings) {let sum = 0;// Always 10 Rodsfor (let i = 0; i < 10; i++) {if (rings.includes(`B${i}`) && rings.includes(`G${i}`) && rings.includes(`R${i}`)) {sum+=1;}}return sum;};console.log(countPoints(rings));
const binarySearch = (arr, item) => {let l = 0,r = arr.length - 1;while (l <= r) {const mid = Math.floor((l + r) / 2);const guess = arr[mid];if (guess === item) return mid;if (guess > item) r = mid - 1;else l = mid + 1;}return -1;};binarySearch([1, 2, 3, 4, 5], 1); // 0binarySearch([1, 2, 3, 4, 5], 5); // 4binarySearch([1, 2, 3, 4, 5], 6); // -1
//Disclaimer: I do not condone mass web scraping of ESPN websites, and this is just theoretical code that hasn't been used.//Scrape player stats off of https://www.espn.com/nfl/team/roster/_/name/phi/philadelphia-eagles//Example player JS object/*{"shortName": "S. Opeta","name": "Sua Opeta","href": "http://www.espn.com/nfl/player/_/id/3121009/sua-opeta","uid": "s:20~l:28~a:3121009","guid": "dec19157-e984-f981-3724-498281328c97","id": "3121009","height": "6' 4\"","weight": "305 lbs","age": 27,"position": "G","jersey": "78","birthDate": "08/15/96","headshot": "https://a.espncdn.com/i/headshots/nfl/players/full/3121009.png","lastName": "Sua Opeta","experience": 4,"college": "Weber State"}*///The page needs to be focused, so you have to put this code in a bookmarklet and click the page before clicking it. Allegedly.navigator.clipboard.writeText(JSON.stringify(window["__espnfitt__"].page.content.roster.groups.flatMap((group)=>{return group.athletes.map((athlete)=>{//We can assume all football players are above 100 lbs and below 1000 lbs.athlete.weight = parseInt(athlete.weight.substring(0,3));if(athlete.experience == "R") athlete.experience = 0;else athlete.experience = parseInt(athlete.experience);//We can assume players are at least 1 foot, or under 10 feet tall.athlete.inches = 12 * parseInt(athlete.height.substring(0, 1)); //Add feet in inchesathlete.inches += parseInt(athlete.height.substring(2).replaceAll("\"", "").trim()); //Add remaining inchesconst monthDayYear = athlete.birthDate.split("/");athlete.birthMonth = parseInt(monthDayYear[0]);athlete.birthDay = parseInt(monthDayYear[1]);athlete.birthYear = parseInt(monthDayYear[2]);//The only really useful stuff we get from this is Height, weight, left handedness, age, position, and birthdayreturn athlete;});}), null, "\t")).then(null, ()=>{alert("That failed.")});//Changes all the team links on this page https://www.espn.com/nfl/stats/team to the team's roster for easier scraping$$("table > tbody > tr > td > div > div > a").forEach((elm)=>{elm.setAttribute("href", elm.getAttribute("href").replace("team/", "team/roster/"));});