Leetcode 202 Happy Number 弗洛伊德判环

 1 class Solution {
 2 public:
 3     int change(int n){
 4         int ans  = 0;
 5         for ( ; n!=0 ; ans+= (n%10)*(n%10),n/=10);
 6         return ans;
 7     }
 8     bool isHappy(int n) {
 9         int one = n;
10         int two = n;
11         while(1){
12             one = change(one);
13             two = change(change(two));
14             if(one == 1 || two == 1) return true;
15             if(one == two) return false;
16         }
17         
18     }
19 };