LeetCode/solutions/202. Happy Number.md

# [202. Happy Number](https://leetcode.com/problems/happy-number/description/)
# 思路
按照题目的意思进行循环，判断每次循环结果是否为1，若是则返回true，否则用map记录结果，然后修改n进行下一次循环。  
# C++
```
class Solution {
private:
    int count_sum(int n){ // 定义题目中所述的求和函数
        int sum = 0;
        while(n > 0){
            sum += (n % 10) * (n % 10);
            n /= 10;
        }
        return sum;
    }
public:
    bool isHappy(int n) {
        map<int, int>mp;
        while(n){
            if(n == 1) return true;
            if(mp[n] == 1) return false;
            mp[n] = 1;
            n = count_sum(n);
        }
        return false;
    }
};
```