leetCode(29):Happy Number 分类： leetCode 2015-07-03 07:55 141人阅读 评论(0) 收藏

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

class Solution {
public:
bool isHappy(int n) {
map<int,int> value;
while(n!=1)
{
value
=1;
int remain;
int tmp=0;
while(n!=0)
{
remain=n%10;
tmp+=remain*remain;
n=n/10;
}
n=tmp;
if(value.find(n)!=value.end())
break;//是否已经出现过
}
if(n!=1)
return false;
return true;

}
};