Write an algorithm to determine if a number 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, 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.
Example: 19 is a happy number
- 12 + 92 = 82
- 82 + 22 = 68
- 62 + 82 = 100
- 12 + 02 + 02 =
1
Credits:
Special thanks to @mithmatt and @ts for
adding this problem and creating all test cases.
This algorithm need to validate its digits.
class Solution: # @param {integer} n # @return {boolean} def isHappy(self, n): val = set() while n not in val: val.add(n) newn = 0 while n != 0: newn += (n % 10) * (n % 10) n /= 10 n = newn if n == 1: return True return False
时间: 2024-10-12 22:48:22