[leetcode] 1013. Pairs of Songs With Total Durations Divisible by 60 : https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60/

Pairs of Songs With Total Durations Divisible by 60.cpp

class Solution {
public:
    int numPairsDivisibleBy60(vector<int>& time) {
        map<int, int> m;
        int answer = 0;
        for(int i=0;i<time.size();i++){
            int rest = time[i] % 60;
            m[rest]++;
        }
        for(map<int,int>::iterator it = m.begin(); it != m.end(); it++){
            pair<int,int> A = *it;
            pair<int,int> B = {60 - A.first, m[60 - A.first]};
            cout<<A.first <<" "<<A.second<<endl;
            if(A.second == 0) continue;
            if(A.first == B.first || A.first == 0)
                answer += A.second * (A.second - 1) / 2;
            else
                answer += A.second * B.second;
            m[B.first] = 0;
        }
        return answer;
    }
};