Nylas Secret Santa

README.md

Tested on Node v.15.14.0

To run script

node index.js

index.js

const getRandomIndex = (start,end) => {
	return Math.trunc(Math.random() * (end-start) + start);
}
const giftExchange = (arr)=>{
	let length = arr.length;
	if (length <= 2) {
		throw new Error("Insufficient friends");
	}
	let map = new Map();
	while ([...map.entries()].length < length) {
		let gifter = arr.shift();
		let index = getRandomIndex(0,arr.length-1);
		if ([...map.values()].includes(arr[index]) || map.get(arr[index]) === gifter){
			arr.push(gifter);
			continue;
		}
		map.set(gifter,arr[index]);
		arr.push(gifter);
	}
	let output= "";
	for (const [gifter,receiver] of map.entries()){
		output+= `${gifter} gives a gift to ${receiver}\n`;
	}
	return output;
}

const run = () => {
	console.log(giftExchange(["Susan","Beth","Abe","Ardi", "Quan"]));
	console.log(giftExchange(["Susan","Beth","Abe","Ardi", "Quan","Nick","Tom","Hamsa","Helen"]));
	console.log(giftExchange(["Susan","Beth"]));
}

run()