1383. Maximum Performance of a Team

class Solution {
    public int maxPerformance(int n, int[] speed, int[] efficiency, int k) {
        int MOD = (int) (1e9 + 7);
        
        int[][] engineers = new int[speed.length][2];
        for (int i = 0; i < speed.length; i++) {
            engineers[i] = new int[]{speed[i], efficiency[i]};
        }
        // Sort efficiency in descending order.
        Arrays.sort(engineers, new Comparator<int[]> () {
            @Override
            public int compare(int[] o1, int[] o2) {
                return o2[1] - o1[1];
            }
        });
        
        // Maintain a pq to track of the minimum speed in the group.
        PriorityQueue<Integer> pq = new PriorityQueue<>(k);
        
        long res = Long.MIN_VALUE;
        long totalSpeed = 0;
        for (int[] engineer : engineers) {
            if (pq.size() == k) {
                totalSpeed -= pq.poll(); // layoff the one with min speed
            }
            pq.add(engineer[0]);
            totalSpeed = (totalSpeed + engineer[0]);
            res = Math.max(res, (totalSpeed * engineer[1]));
        }
        return (int) (res % MOD);
        
    }
}