1 class Solution 
 2 {
 3     struct cmp
 4     {
 5         bool operator ()(vector<int> &a, const vector<int> &b)
 6         {
 7             // < :大顶堆
 8             // > :小顶堆
 9             return a[0]+a[1] > b[0]+b[1];
10         }
11     };
12 public:
13     vector<vector<int>> kSmallestPairs(vector<int>& nums1, vector<int>& nums2, int k) 
14     {
15         priority_queue<vector<int>, vector<vector<int>>, cmp> pq;
16         for(auto n1:nums1)
17         {
18             for(auto n2:nums2)
19             { 
20                 pq.push({{n1,n2}});
21             }
22         }
23         while(!pq.empty())
24         {
25             cout << (pq.top())[0] << " " << (pq.top())[1] << endl;
26             pq.pop();
27         }
28         vector<vector<int>> res;
29         for(int i = 0; i < k; ++i)
30         {
31             if(pq.empty()) break;
32             res.push_back(pq.top());
33             pq.pop();
34         }
35         return res;
36     }
37 };