• Feb 3, 2021 •C S
0 likes • 2 views
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
• Nov 19, 2022 •CodeCatch
// `arr` is an array const clone = arr => arr.slice(0); // Or const clone = arr => [...arr]; // Or const clone = arr => Array.from(arr); // Or const clone = arr => arr.map(x => x); // Or const clone = arr => JSON.parse(JSON.stringify(arr)); // Or const clone = arr => arr.concat([]);
const longestPalindrome = (s) => { if(s.length === 1) return s const odd = longestOddPalindrome(s) const even = longestEvenPalindrome(s) if(odd.length >= even.length) return odd if(even.length > odd.length) return even }; const longestOddPalindrome = (s) => { let longest = 0 let longestSubStr = "" for(let i = 1; i < s.length; i++) { let currentLongest = 1 let currentLongestSubStr = "" let left = i - 1 let right = i + 1 while(left >= 0 && right < s.length) { const leftLetter = s[left] const rightLetter = s[right] left-- right++ if(leftLetter === rightLetter) { currentLongest += 2 currentLongestSubStr = s.slice(left+1, right) } else break } if(currentLongest > longest) { if(currentLongestSubStr) longestSubStr = currentLongestSubStr else longestSubStr = s[i] longest = currentLongest } } return longestSubStr } const longestEvenPalindrome = (s) => { let longest = 0 let longestSubStr = "" for(let i = 0; i < s.length - 1; i++) { if(s[i] !== s[i+1]) continue; let currentLongest = 2 let currentLongestSubStr = "" let left = i - 1 let right = i + 2 while(left >= 0 && right < s.length) { const leftLetter = s[left] const rightLetter = s[right] left-- right++ if(leftLetter === rightLetter) { currentLongest += 2 currentLongestSubStr = s.slice(left+1, right) } else break } if(currentLongest > longest) { if(currentLongestSubStr) longestSubStr = currentLongestSubStr else longestSubStr = s[i] + s[i+1] longest = currentLongest } } return longestSubStr } console.log(longestPalindrome("babad"))
• Feb 5, 2021 •LeifMessinger
0 likes • 3 views
class Timer{ start(){ this.startTime = Date.now(); } stop(){ const dt = Date.now() - this.startTime; console.log(dt); return dt; } getExecTime(fun, asynchronous){ return asynchronous ? this.getAsyncExecTime(fun) : this.getSyncExecTime(fun); } getSyncExecTime(fun){ this.start(); fun(); return this.stop(); } async getAsyncExecTime(fun){ this.start(); await fun(); return this.stop(); } static average(fun, numTimes, asynchronous = false){ const times = []; const promises = []; let timer = new Timer(); if(asynchronous){ for(let i = 0; i < numTimes; i++){ timer.getAsyncExecTime(fun); } }else{ for(let i = 0; i < numTimes; i++){ timer.getSyncExecTime(fun); } } return (times => times.reduce(((sum, acc) => sume + acc), 0) / times.length); } static async timeAsync(fun, numTimes){ if(numTimes <= 1) return new Timer().getAsyncExecTime(fun); const promises = []; let timer = new Timer(true); for(let i = 0; i < numTimes; i++){ promises.push(fun().catch((e)=>{})); } try{ await Promise.all(promises).catch((e)=>{}); }catch(e){ //do absolutely nothing } return timer.stop(); } constructor(start = false){ if(start) this.start(); } }
• Sep 13, 2023 •C S
0 likes • 6 views
/** * @param {number[]} nums * @return {boolean} */ var containsDuplicate = function(nums) { return new Set(nums).size !== nums.length };
• Nov 18, 2022 •AustinLeath
//use this with canvas file finder function NewTab(testing) { window.open(testing, "_blank"); } for(test in results) { var testing = 'https://unt.instructure.com/files/' + test + '/download'; NewTab(testing); }