Leetcode - 202. Happy Number

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

Solution 1

/**
 * @param {number} n
 * @return {boolean}
 */
var isHappy = function (n) {
  let set = new Set();

  while (!set.has(n)) {
    set.add(n);
    let s = n.toString();
    n = 0;
    for (let i = 0; i < s.length; ++i) {
      n += squares[s[i]];
    }
    if (n === 1) return true;
  }

  return false;
};

const squares = {
  0: 0,
  1: 1,
  2: 4,
  3: 9,
  4: 16,
  5: 25,
  6: 36,
  7: 49,
  8: 64,
  9: 81,
};