LeetCode : 373. Find K Pairs with Smallest Sums

[congr]

https://leetcode.com/problems/find-k-pairs-with-smallest-sums/

[congr]

Heap used, but it is very slow.

[congr]

class Solution {
    public List<int[]> kSmallestPairs(int[] nums1, int[] nums2, int k) {
        List<int[]> list = new ArrayList();
        if (k == 0) return list;
        if (nums1.length == 0 || nums2.length == 0) return list;

        PriorityQueue<int[]> pq = new PriorityQueue<int[]>((a,b) -> (b[0]+b[1]) - (a[0]+a[1]));

        for (int i = 0; i<nums1.length; i++) {
            for (int j = 0; j<nums2.length; j++) {
                pq.add(new int[]{nums1[i], nums2[j]});
                if (pq.size() > k) pq.remove();
            }
        }

        while (!pq.isEmpty()) list.add(pq.remove());
        return list;
    }
}