Happy Number:

[blade-sensei]

A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.

Return True if n is a happy number, and False if not.

Input: 19
Output: true
Explanation: 
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1

[blade-sensei]

Brute force but really bad perform

var isHappy = function(n) {
  const alreadyFind = [];
  if (n <= 0) return false;
    let numberToCheck = n;
    while (numberToCheck !== 1) {
      let numberString = numberToCheck.toString();
      numberString = numberString.split('');
      numberString = numberString.map((number) => {
        return Math.pow(Number(number), 2);
      });
      numberToCheck = numberString.reduce((p, c) => p + c);
      if (alreadyFind.includes(numberToCheck)) {
        return false;
      } else {
        alreadyFind.push(numberToCheck);
      }
      console.log(numberToCheck, alreadyFind)

    }
    return true;
};

[blade-sensei]

☝️ Here we need to return false when we see that this will we a infinite loop.
thats we need to chech isAlreadyfind