【LeetCode】(202)Happy Number(Easy)

题目

Happy Number

Total Accepted: 26154 Total
Submissions: 82078My Submissions

Question
Solution

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

解析

循环判断就好了，直接上代码

class Solution {
public:
bool isHappy(int n) {
int m = 0;
while (n!=0)
{
m += (n%10)*(n%10);
n = n/10;
}
if (m == 1)
{
return true;
}
else if (m<9)
{
return false;
}
else
return isHappy(m);
}
};