May 08

Author: siddydutta

2025-05-May-LeetCoding-Challenge/Find Minimum Time to Reach Last Room II.py

@@ -0,0 +1,36 @@
+from heapq import heappop, heappush
+
+
+class Solution:
+    DIRS = ((0, -1), (0, 1), (1, 0), (-1, 0))
+
+    def minTimeToReach(self, moveTime: list[list[int]]) -> int:
+        """Dijkstra's algorithm-based implementation."""
+        n, m = len(moveTime), len(moveTime[0])
+        heap = [(0, (0, 0), True)]  # time, (x, y), flag: False 1, True 2
+        visited = {(0, 0)}
+        while heap:
+            time, (x, y), flag = heappop(heap)
+            if x == n - 1 and y == m - 1:
+                return time
+            for dx, dy in self.DIRS:
+                nx, ny = x + dx, y + dy
+                if 0 <= nx < n and 0 <= ny < m and (nx, ny) not in visited:
+                    leave_time = max(moveTime[nx][ny], time) + (int(not flag) + 1)
+                    heappush(heap, (leave_time, (nx, ny), not flag))
+                    visited.add((nx, ny))
+        return 0
+
+
+def main():
+    moveTime = [[0, 4],
+                [4, 4]]
+    assert Solution().minTimeToReach(moveTime) == 7
+
+    moveTime = [[0, 0, 0],
+                [0, 0, 0]]
+    assert Solution().minTimeToReach(moveTime) == 6
+
+
+if __name__ == '__main__':
+    main()

2025-05-May-LeetCoding-Challenge/README.md

@@ -11,7 +11,7 @@
 | May 05 | [790. Domino and Tromino Tiling](https://leetcode.com/problems/domino-and-tromino-tiling/) | Medium | Solved |
 | May 06 | [1920. Build Array from Permutation](https://leetcode.com/problems/build-array-from-permutation/) | Easy | Solved |
 | May 07 | [3341. Find Minimum Time to Reach Last Room I](https://leetcode.com/problems/find-minimum-time-to-reach-last-room-i/) | Medium | Solved |
-| May 08 | []() |  |  |
+| May 08 | [3342. Find Minimum Time to Reach Last Room II](https://leetcode.com/problems/find-minimum-time-to-reach-last-room-ii/) | Medium | Solved |
 | May 09 | []() |  |  |
 | May 10 | []() |  |  |
 | May 11 | []() |  |  |
@@ -41,5 +41,5 @@
 | Level  | Problems | Solved | Unsolved |
 | ---    | --- | --- | --- |
 | Easy   | 2 | 2 | 0 |
-| Medium | 4 | 4 | 0 |
+| Medium | 5 | 5 | 0 |
 | Hard   | 1 | 1 | 0 |