Happy Number
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
class Solution {
public:
bool isHappy(int n) {
if (n == 1) return true;
int m ;
map<int,int>a;
while (n != 1) {
if (a[n] == 1) break;
a[n] = 1;
m = 0 ;
while (n) {
m += (n%10) * (n%10) ;
n = n/10 ;
}
n = m ;
if (n == 1) return true;
}
return false;
}
};版权声明：本文为博主原创文章，未经博主允许不得转载。
原文：http://blog.csdn.net/u014705854/article/details/47061537