1public class Solution {
2    private int DFS(int[][] grid, int x, int y) {
3        if (x < 0 || y < 0 || x >= grid.Length || y >= grid[0].Length || grid[x][y] == 0) return 0;
4
5        int originalGold = grid[x][y];
6        grid[x][y] = 0; // Mark as visited
7        int maxGold = 0;
8        int[][] directions = new int[][] { new int[] {1, 0}, new int[] {-1, 0}, new int[] {0, 1}, new int[] {0, -1} };
9        foreach(var dir in directions) {
10            maxGold = Math.Max(maxGold, DFS(grid, x + dir[0], y + dir[1]));
11        }
12        grid[x][y] = originalGold; // Backtrack
13        return originalGold + maxGold;
14    }
15
16    public int GetMaximumGold(int[][] grid) {
17        int maxGold = 0;
18        for (int i = 0; i < grid.Length; i++) {
19            for (int j = 0; j < grid[0].Length; j++) {
20                if (grid[i][j] > 0) {
21                    maxGold = Math.Max(maxGold, DFS(grid, i, j));
22                }
23            }
24        }
25        return maxGold;
26    }
27}

1