Write an algorithm to determine if a number n is "happy number".

        Write an algorithm to determine if a number n 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.

Return True if n is a happy number, and False if not.

Input: 19
Output: true
Explanation: 
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1

class Solution {
public:
    bool isHappy(int n) {
    if(n==1||n==7)return true;
        if(n>=0&&n<=9)
            return false;
unordred_map<int,int> mp;
    while(1)
 {
        int sum=0;
        while(n!=0)
        {
            sum+=pow(n%10,2);
            n/=10;
        }
         if(sum==1)return true;
        if(mp[sum]==0)
        mp[sum]++;
        else
            return false;
        
      n=sum;
  }
       return false;
    }
};
-------------------------------------------------------------------------------------------------------------------------------------
class Solution {
public:
    bool isHappy(int n) {
    if(n==1||n==7)return true;
        if(n>=0&&n<=9)
            return false;
        int sum=0;
        while(n!=0)
        {
            sum+=pow(n%10,2);
            n/=10;
        }
     
       return isHappy(sum);
    }
};