202. Happy Number (INT)

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:
    int getSquare(int num){ //because square operation is very often, so enum the result
        switch(num){
            case : return ;
            case : return ;
            case : return ;
            case : return ;
            case : return ;
            case : return ;
            case : return ;
            case : return ;
            case : return ;
            case : return ;
        }
    }
    bool isHappy(int n) {
        if(n == ) return false;

        set<int> squareSum;
        return dfs(n, squareSum);
    }

    bool dfs(int n, set<int>& squareSum){
        int tmp;
        int sum = ;
        while(n){
            tmp = n%;
            sum += getSquare(tmp);
            n /= ;
        }
        if(sum == ) return true;
        else if(squareSum.find(sum)!=squareSum.end()) return false;
        else {
            squareSum.insert(sum);
            return dfs(sum, squareSum);
        }
    }
};