(leetcode) Happy Number 

 1 class Solution {
 2 public:
 3     int calculate(int n)
 4     {
 5         int res = 0;
 6         while(n > 0)
 7         {
 8             int tmp = n%10;
 9             res = res + tmp*tmp;
10             n /= 10;
11         }
12         return res;
13     }
14     bool isHappy(int n) {
15         if(n == 1) return true;
16         unordered_set<int> Tocheck;
17         while(n)
18         {
19             int tmp = calculate(n);
20             if(1 == tmp) return true;
21             else
22             {
23                 if(Tocheck.find(tmp) != Tocheck.end()) 
24                     return false;
25                 else
26                     Tocheck.insert(tmp);
27             }
28             n = tmp;
29         }
30     }
31 };

 

posted @ 2015-08-04 15:57  sunalive  Views(122)  Comments(0)    收藏  举报