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count substrings

0 likes • Nov 19, 2022 • 0 views
JavaScript
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hamming distance

0 likes • Nov 19, 2022 • 0 views
JavaScript
const hammingDistance = (num1, num2) =>
((num1 ^ num2).toString(2).match(/1/g) || '').length;
hammingDistance(2, 3); // 1

luhnCheck implementation

0 likes • Nov 19, 2022 • 0 views
JavaScript
const luhnCheck = num => {
let arr = (num + '')
.split('')
.reverse()
.map(x => parseInt(x));
let lastDigit = arr.splice(0, 1)[0];
let sum = arr.reduce(
(acc, val, i) => (i % 2 !== 0 ? acc + val : acc + ((val *= 2) > 9 ? val - 9 : val)),
0
);
sum += lastDigit;
return sum % 10 === 0;
};
luhnCheck('4485275742308327'); // true
luhnCheck(6011329933655299); // true
luhnCheck(123456789); // false

Scrape twitter

0 likes • Sep 2, 2023 • 9 views
JavaScript
//Allegedly never tested on the twitter website
function scrapeScreen(){
let articles = Array.from(document.getElementsByTagName("article"));
let results = [];
for(let tweet of articles){
const isAnAd = Array.from(tweet.querySelectorAll("span")).map((e)=>e.textContent).includes("Ad");
if(isAnAd){
//console.log(tweet, "is an ad. Skipping...");
continue;
}
const userName = tweet.querySelector("[data-testid='User-Name'] > div:nth-child(2) > div > div")?.textContent;
const tweetContent = tweet.querySelector("[data-testid='tweetText']")?.textContent;
const timeStamp = tweet.querySelector("time")?.getAttribute("datetime");
const tweetLink = tweet.querySelector("time")?.parentElement?.getAttribute("href");
if((!userName) || (!tweetContent)) continue;
results.push({
username: userName,
tweetText: tweetContent,
timeStamp: timeStamp,
tweetLink: tweetLink
});
}
return results;
}
let scraped = scrapeScreen();
setInterval(()=>{
scraped = scraped.concat(
scrapeScreen().filter((tweet)=>{
for(let scrapedTweet of scraped){
if(scrapedTweet.username == tweet.username && scrapedTweet.tweetText == tweet.tweetText) return false;
}
return true;
})
);
}, 500); //Scrape everything on the screen twice a second
window.scrollIntervalId = setInterval(function(){
window.scrollBy(0, 1000);
}, 500); //Scroll for me
//http://bgrins.github.io/devtools-snippets/#console-save
(function(console){
console.save = function(data, filename){
if(!data) {
console.error('Console.save: No data')
return;
}
if(!filename) filename = 'console.json'
if(typeof data === "object"){
data = JSON.stringify(data, undefined, '\t')
}
var blob = new Blob([data], {type: 'text/json'}),
e = document.createEvent('MouseEvents'),
a = document.createElement('a')
a.download = filename
a.href = window.URL.createObjectURL(blob)
a.dataset.downloadurl = ['text/json', a.download, a.href].join(':')
e.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null)
a.dispatchEvent(e)
}
})(console)
setTimeout(()=>{
clearTimeout(window.scrollIntervalId);
delete window.scrollIntervalId;
console.save(scraped, "TwitterScrape" + Date.now() + ".json");
}, 60 * 1000 * 20); //Twenty minutes

test

0 likes • Sep 10, 2023 • 3 views
JavaScript
let test = 1;

tree traversal

0 likes • Nov 19, 2022 • 1 view
JavaScript
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']

Bitwise XOR operator

0 likes • Nov 19, 2022 • 0 views
JavaScript
//JavaScript program to swap two variables
//take input from the users
let a = prompt('Enter the first variable: ');
let b = prompt('Enter the second variable: ');
// XOR operator
a = a ^ b
b = a ^ b
a = a ^ b
console.log(`The value of a after swapping: ${a}`);
console.log(`The value of b after swapping: ${b}`);