aloalgoHappy Number
Easy
You are given a positive integer n.
Your task is to determine whether n is a happy number. A happy number is defined by the following process: starting with the given number, replace it with the sum of the squares of its digits, and repeat until the number either equals 1 or enters an endless cycle.
Note that:
- A number is happy if this process eventually reaches
1. - A number is not happy if this process enters a cycle that does not include
1.
Return true if n is a happy number, and false otherwise.
Example 1
Input
19
Output
True
Explanation:
1² + 9² = 82 → 8² + 2² = 68 → 6² + 8² = 100 → 1² + 0² + 0² = 1. The process reaches 1, so 19 is a happy number.
Example 2
Input
2
Output
False
Explanation:
2 → 4 → 16 → 37 → 58 → 89 → 145 → 42 → 20 → 4 → … The process enters a cycle and never reaches 1, so 2 is not a happy number.
Example 3
Input
1
Output
True
Explanation:
1² = 1. The number is already 1, so it is a happy number.
Input
19
Output
True