2160. Minimum Sum of Four Digit Number After Splitting Digits

class Solution {
public:
    int minimumSum(int num) {
       vector<int> result;

       while(num>0)
       {
           result.push_back(num%10);
           num /= 10;
       }
       sort(result.begin(), result.end());

       int a = result[0]*10 + result[2];
       int b = result[1]*10 + result[3];

       return (a+b);
    }
};