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quick sort

Nov 19, 2022CodeCatch
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More JavaScript Posts

Clone an array

Nov 19, 2022CodeCatch

0 likes • 1 view

// `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([]);

tree traversal

Nov 19, 2022CodeCatch

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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; // true
tree.find(12).isLeaf; // false
tree.find(121).isLeaf; // true
tree.find(121).parent.value; // 'BC'
tree.remove(12);
[...tree.postOrderTraversal()].map(x => x.value);
// ['AC', 'AB']

bucket sort

Nov 19, 2022CodeCatch

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const bucketSort = (arr, size = 5) => {
const min = Math.min(...arr);
const max = Math.max(...arr);
const buckets = Array.from(
{ length: Math.floor((max - min) / size) + 1 },
() => []
);
arr.forEach(val => {
buckets[Math.floor((val - min) / size)].push(val);
});
return buckets.reduce((acc, b) => [...acc, ...b.sort((a, b) => a - b)], []);
};
bucketSort([6, 3, 4, 1]); // [1, 3, 4, 6]

React Short Circuit Evaluation

Feb 3, 2021C S

0 likes • 1 view

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

ESPN Web Scrape

Oct 15, 2023LeifMessinger

0 likes • 7 views

//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 inches
athlete.inches += parseInt(athlete.height.substring(2).replaceAll("\"", "").trim()); //Add remaining inches
const 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 birthday
return 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/"));
});

List Largest Files Google Drive

Nov 16, 2023LeifMessinger

0 likes • 7 views

function filePath(file){
let folders = file.getParents();
const parents = [];
function makePathString(folderArray){
let path = "";
folderArray.forEach((folder)=>{
path += "/" + folder.getName();
});
return path;
}
while (folders.hasNext()) {
const folder = folders.next(); //This should hopefully remove that folder from the iterator
parents.unshift(folder);
}
return makePathString(parents);
}
function myFunction() {
const myEmail = Session.getEffectiveUser().getEmail();
Logger.log("My email is " + myEmail);
// Log the name of every file in the user's Drive.
var fileIterator = DriveApp.getFiles();
const files = []; //List of [File, size] entries
const filesMaxSize = 10;
while (fileIterator.hasNext()) {
var file = fileIterator.next();
const owner = file.getOwner();
//Only files I own
if((!(owner)) || (!(owner.getEmail)) || owner.getEmail() != myEmail){
continue;
}
const entry = [file, file.getSize()];
function slideUp(arr, index){
//Let's keep sliding it up so we don't have to sort it at the end.
for(let i = index; i > 0; --i){ //Stops at 1
const nextFile = arr[i-1];
if(nextFile[1] > entry[1]){
break;
}else{
//Swap with the next file to slide the file up
const temp = arr[i];
arr[i] = arr[i - 1];
arr[i - 1] = temp;
}
}
}
if(files.length < filesMaxSize){
files.push(entry);
slideUp(files, files.length - 1);
}else{
if(entry[1] > files[files.length - 1][1]){ //If it's bigger than the smallest file in the list.
files[files.length - 1] = entry; //Replace the smallest file
slideUp(files, files.length - 1); //Slide it up
}
}
}
for(let i = 0; i < filesMaxSize; ++i){
const file = files[i][0];
const size = files[i][1];
Logger.log(size + "\t" + filePath(file) + "/" + file.getName() + "\t" + file.getOwner().getName());
}
}