Create path-with-maximum-gold.cpp

Author: kamyu104

C++/path-with-maximum-gold.cpp

@@ -0,0 +1,37 @@
+// Time:  O(m^2 * n^2)
+// Space: O(m * n)
+
+class Solution {
+public:
+    int getMaximumGold(vector<vector<int>>& grid) {
+        int result = 0;
+        for (int i = 0; i < grid.size(); ++i) {
+            for (int j = 0; j < grid[0].size(); ++j) {
+                if (grid[i][j]) {
+                    result = max(result, backtracking(&grid, i, j));
+                }
+            }
+        }
+        return result;
+    }
+
+private:
+    int backtracking(vector<vector<int>> *grid, int i, int j) {
+        static const vector<pair<int, int>> directions{{0, 1}, {1, 0},
+                                                       {0, -1}, {-1, 0}};
+        int result = 0;
+        (*grid)[i][j] *= -1;
+        for (const auto& [dx, dy] : directions) {
+            int ni = i + dx;
+            int nj = j + dy;
+            if (!(0 <= ni && ni < grid->size() &&
+                  0 <= nj && nj < (*grid)[0].size() &&
+                  (*grid)[ni][nj] > 0)) {
+                continue;
+            }
+            result = max(result, backtracking(grid, ni, nj));
+        }
+        (*grid)[i][j] *= -1;
+        return (*grid)[i][j] + result;
+    }
+};