K Max Sum Combinations

#include<bits/stdc++.h>
vector<int> kMaxSumCombination(vector<int> &a, vector<int> &b, int n, int k){
    priority_queue<pair<int,pair<int,int>>> q;
    sort(a.begin(),a.end());
    sort(b.begin(),b.end());
    q.push(make_pair(a[n-1]+b[n-1],make_pair(n-1,n-1)));
    map<pair<int,int>,bool> mp;
    mp[make_pair(a[n-1],b[n-1])]=true;
    vector <int> res;
    for(int l=0;l<k;l++){
        pair<int,pair<int,int>> temp=q.top();
        q.pop();
        res.push_back(temp.first);
        int i=temp.second.first;
        int j=temp.second.second;
        pair<int,int> check=make_pair(i-1,j);

        if(i>=0 && !mp[check]){
            q.push(make_pair(a[i-1]+b[j],make_pair(i-1,j)));
            mp[make_pair(i-1,j)]=true;
        }
        check.first=i;
        check.second=j-1;
        if(j>=0 && !mp[check]){
            q.push(make_pair(a[i]+b[j-1],make_pair(i,j-1)));
            mp[make_pair(i,j-1)]=true;
        }
    }
    return res;
}