826. Most Profit Assigning Work 

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
class Solution {
    public int maxProfitAssignment(int[] difficulty, int[] profit, int[] worker) {
        int[][] pairs = new int[difficulty.length][];
        for (int i = 0; i < pairs.length; i++) {
            pairs[i] = new int[]{difficulty[i], profit[i]};
        }
        Arrays.sort(pairs, Comparator.comparingInt(o -> o[0]));
        for (int i = 1; i < pairs.length; i++) {
            pairs[i][1] = Math.max(pairs[i - 1][1], pairs[i][1]);
        }

        int maxProfit = 0;
        for (int w : worker) {
            maxProfit += findMaxProfit(pairs, w);
        }
        return maxProfit;
    }

    private int findMaxProfit(int[][] pairs, int w) {
        int left = 0, right = pairs.length - 1;
        while (left <= right) {
            int mid = (left + right) >>> 1;
            if (pairs[mid][0] < w) {
                left = mid + 1;
            } else if (pairs[mid][0] > w) {
                right = mid - 1;
            } else {
                left = mid + 1;
            }
        }

        // now: right, left
        return right == -1 ? 0 : pairs[right][1];
    }
}

Two Pointers

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
class Solution {
    public int maxProfitAssignment(int[] difficulty, int[] profit, int[] worker) {
        int[][] pairs = new int[difficulty.length][2];
        for (int i = 0; i < pairs.length; i++) {
            pairs[i][0] = difficulty[i];
            pairs[i][1] = profit[i];
        }
        Arrays.sort(pairs, Comparator.comparingInt(o -> o[0]));
        for (int i = 1; i < pairs.length; i++) {
            pairs[i][1] = Math.max(pairs[i - 1][1], pairs[i][1]);
        }

        Arrays.sort(worker);
        int ans = 0, maxProfit = 0, i = 0;
        for (int w : worker) {
            while (i < pairs.length && pairs[i][0] <= w) {
                maxProfit = Math.max(maxProfit, pairs[i][1]);
                i++;
            }
            ans += maxProfit;
        }

        return ans;
    }
}

References

826. Most Profit Assigning Work