【leetcode】Happy Number

標籤：

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

1^2 + 9^2 = 82
8^2 + 2^2 = 68
6^2 + 8^2 = 100
1^2 + 0^2 + 0^2 = 1

 

 1 class Solution { 2 public: 3     int cnt=0; 4  5     int Sum(int m) 6     { 7         cnt++; 8         int sum=0; 9         int tmp=0;10         while(m>0)11         {12             tmp=m%10;13             sum=sum+pow(tmp,2);14             m=m/10;15         }16         if(sum==1)17         {18             return 1;19         }20         if(cnt>=100&&sum!=1)21         {22             return 0;23         }24         25         Sum(sum);26     }27 28     bool isHappy(int n) {29         if(n==0) return false;30 31         if(Sum(n)==1) return true;32         if(Sum(n)==0) return false;33     }34 };

 

【leetcode】Happy Number