let nums = [1,2,3,1]

var containsDuplicate = function(nums) {
    let obj = {};
    for(let i =0; i< nums.length; i++){
        if(obj[nums[i]]){
            obj[nums[i]] += 1;
            return true;
        }else{
            obj[nums[i]] = 1;
        }
    }
    return false;
};

console.log(containsDuplicate(nums));

const euclideanDistance = (a, b) =>
  Math.hypot(...Object.keys(a).map(k => b[k] - a[k]));
  
euclideanDistance([1, 1], [2, 3]); // ~2.2361
euclideanDistance([1, 1, 1], [2, 3, 2]); // ~2.4495

//Upvotes comments according to a regex pattern. I tried it out on https://www.reddit.com/r/VALORANT/comments/ne74n4/please_admire_this_clip_precise_gunplay_btw/
//Known bugs:
	//If a comment was already upvoted, it gets downvoted
	//For some reason, it has around a 50-70% success rate. The case insensitive bit works, but I think some of the query selector stuff gets changed. Still, 50% is good

let comments = document.getElementsByClassName("_3tw__eCCe7j-epNCKGXUKk"); //Comment class
let commentsToUpvote = [];
const regexToMatch = /wtf/gi;
for(let comment of comments){
	let text = comment.querySelector("._1qeIAgB0cPwnLhDF9XSiJM"); //Comment content class
	if(text == undefined){
	continue;
	}
	text = text.textContent;
	if(regexToMatch.test(text)){
	console.log(text);
	commentsToUpvote.push(comment);
	}
}
function upvote(comment){
	console.log(comment.querySelector(".icon-upvote")); //Just showing you what it's doing
	comment.querySelector(".icon-upvote").click();
}
function slowRecurse(){
	let comment = commentsToUpvote.pop(); //It's gonna go bottom to top but whatever
	if(comment != undefined){
	upvote(comment);
	setTimeout(slowRecurse,500);
	}
}
slowRecurse();

const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');

// Connection URL
const url = 'mongodb://localhost:27017';

// Database Name
const dbName = 'myproject';

// Use connect method to connect to the server
MongoClient.connect(url, function(err, client) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  const db = client.db(dbName);

  client.close();
});

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();
	}
}

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