202410132135
tags: #hash-map

var isHappy = function(n) {
	const visited = new Set([n]);
	let num = n;
	while (num !== 1) {
		let newNum = 0;
		for (const c of num.toString()) {
			newNum += Number(c) * Number(c);
		}
		num = newNum;
		if (visited.has(newNum)) {
			break;
		}
		visited.add(newNum);
	}
	return num === 1;
};

Reference

https://leetcode.com/problems/happy-number/