3945. Digit Frequency Score

You are given an integer n.

The score of n is defined as the sum of d * freq(d) over all distinct digits d, where freq(d) denotes the number of times the digit d appears in n.

Return an integer denoting the score of n.

class Solution {
public:
    int digitFrequencyScore(int n) {
        unordered_map<int,int> freq;
        while(n) {
            freq[n%10]++;
            n /= 10;
        }
        int res = 0;
        for(auto& [k,v] : freq) res += k*v;
        return res;
    }
};