1import java.util.*;
2
3public class MaxPoints {
4    public static int maxPoints(int[][] points) {
5        int m = points.length;
6        int n = points[0].length;
7
8        int[] prevRow = new int[n];
9        System.arraycopy(points[0], 0, prevRow, 0, n);
10
11        for (int i = 1; i < m; i++) {
12            int[] leftToRight = new int[n];
13            int[] rightToLeft = new int[n];
14            int[] currentRow = new int[n];
15
16            leftToRight[0] = prevRow[0];
17            for (int j = 1; j < n; j++) {
18                leftToRight[j] = Math.max(leftToRight[j - 1] - 1, prevRow[j]);
19            }
20
21            rightToLeft[n - 1] = prevRow[n - 1];
22            for (int j = n - 2; j >= 0; j--) {
23                rightToLeft[j] = Math.max(rightToLeft[j + 1] - 1, prevRow[j]);
24            }
25
26            for (int j = 0; j < n; j++) {
27                currentRow[j] = points[i][j] + Math.max(leftToRight[j], rightToLeft[j]);
28            }
29
30            prevRow = currentRow;
31        }
32
33        return Arrays.stream(prevRow).max().getAsInt();
34    }
35
36    public static void main(String[] args) {
37        int[][] points = {{1, 2, 3}, {1, 5, 1}, {3, 1, 1}};
38        System.out.println("Maximum points: " + maxPoints(points));
39    }
40}
41

1
public class Solution {
    public static int MaxPoints(int[][] points) {
        int m = points.Length;
        int n = points[0].Length;

        int[] prevRow = new int[n];
        Array.Copy(points[0], prevRow, n);

        for (int i = 1; i < m; i++) {
            int[] leftMax = new int[n];
            int[] rightMax = new int[n];

            leftMax[0] = prevRow[0];
            for (int j = 1; j < n; j++) {
                leftMax[j] = Math.Max(leftMax[j - 1] - 1, prevRow[j]);
            }

            rightMax[n - 1] = prevRow[n - 1];
            for (int j = n - 2; j >= 0; j--) {
                rightMax[j] = Math.Max(rightMax[j + 1] - 1, prevRow[j]);
            }

            for (int j = 0; j < n; j++) {
                prevRow[j] = points[i][j] + Math.Max(leftMax[j], rightMax[j]);
            }
        }

        int maxPoints = 0;
        foreach (var val in prevRow) {
            if (val > maxPoints) maxPoints = val;
        }

        return maxPoints;
    }

    public static void Main() {
        int[][] points = new int[][] {
            new int[] {1, 2, 3},
            new int[] {1, 5, 1},
            new int[] {3, 1, 1}
        };
        Console.WriteLine("Maximum points: " + MaxPoints(points));
    }
}