Jan 20

Author: siddydutta

2025-01-January-LeetCoding-Challenge/Grid Game.py

@@ -0,0 +1,35 @@
+from itertools import accumulate
+from typing import List
+
+
+class Solution:
+    def gridGame(self, grid: List[List[int]]) -> int:
+        row1 = list(accumulate(grid[0][::-1]))[::-1] + [0]  # postfix sums
+        row2 = [0] + list(accumulate(grid[1]))  # prefix sums
+
+        res = float('inf')
+        for i in range(len(grid[0])):
+            # find col where robot 1 changes rows
+            top_points = row1[i+1]
+            bottom_points = row2[i]
+            # robot1 wants to minimize what robot2 can maximize
+            res = min(res, max(top_points, bottom_points))
+        return res
+
+
+def main():
+    grid = [[2, 5, 4],
+            [1, 5, 1]]
+    assert Solution().gridGame(grid) == 4
+
+    grid = [[3, 3, 1],
+            [8, 5, 2]]
+    assert Solution().gridGame(grid) == 4
+
+    grid = [[1, 3, 1, 15],
+            [1, 3, 3, 1]]
+    assert Solution().gridGame(grid) == 7
+
+
+if __name__ == '__main__':
+    main()

2025-01-January-LeetCoding-Challenge/README.md

@@ -22,8 +22,8 @@
 | January 17 | [2683. Neighboring Bitwise XOR](https://leetcode.com/problems/neighboring-bitwise-xor/) | Medium | Solved |
 | January 18 | [1368. Minimum Cost to Make at Least One Valid Path in a Grid](https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid/) | Hard | Unsolved |
 | January 19 | [407. Trapping Rain Water II](https://leetcode.com/problems/trapping-rain-water-ii/) | Hard | Unsolved |
-| January 20 | [2661. First Completely Painted Row or Column](https://leetcode.com/problems/first-completely-painted-row-or-column/) |  |  |
-| January 21 | []() |  |  |
+| January 20 | [2661. First Completely Painted Row or Column](https://leetcode.com/problems/first-completely-painted-row-or-column/) | Medium | Solved |
+| January 21 | [2017. Grid Game](https://leetcode.com/problems/grid-game/) | Medium | Solved |
 | January 22 | []() |  |  |
 | January 23 | []() |  |  |
 | January 24 | []() |  |  |
@@ -40,5 +40,5 @@
 | Level  | Problems | Solved | Unsolved |
 | ---    | --- | --- | --- |
 | Easy   | 4 | 4 | 0 |
-| Medium | 13 | 11 | 2 |
+| Medium | 14 | 12 | 2 |
 | Hard   | 2 | 0 | 2 |