forked from JoshCrozier/leetcode-javascript
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy path0202-happy-number.js
More file actions
29 lines (28 loc) · 819 Bytes
/
0202-happy-number.js
File metadata and controls
29 lines (28 loc) · 819 Bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
/**
* 202. Happy Number
* https://leetcode.com/problems/happy-number/
* Difficulty: Easy
*
* Write an algorithm to determine if a number n is happy.
*
* 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.
* - 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.
*
* Return true if n is a happy number, and false if not.
*/
/**
* @param {number} n
* @return {boolean}
*/
var isHappy = function(n) {
while (n !== 1) {
n = [...String(n)].reduce((sum, digit) => sum + digit ** 2, 0);
if (n === 4) {
return false;
}
}
return true;
};