Time: 397 ms (55.1%), Space: 40.2 MB (37.24%) - LeetHub

Author: hogan-tech

2343-count-unguarded-cells-in-the-grid/2343-count-unguarded-cells-in-the-grid.py

@@ -0,0 +1,59 @@
+# time complexity: O(m*n)
+# space complexity: O(m*n)
+from collections import deque
+from typing import List
+
+
+class Solution:
+    Guarded = 0
+    Unguarded = 1
+    Guard = 2
+    Wall = 3
+
+    def countUnguarded(self, m: int, n: int, guards: List[List[int]], walls: List[List[int]]) -> int:
+        ROW = m
+        COL = n
+        board = [[self.Unguarded] * COL for _ in range(ROW)]
+        queue = deque()
+        for i, j in guards:
+            board[i][j] = self.Guard
+            queue.append((i, j))
+        for i, j in walls:
+            board[i][j] = self.Wall
+        while queue:
+            currR, currC = queue.popleft()
+
+            for r in range(currR - 1, -1, -1):
+                if board[r][currC] == self.Wall or board[r][currC] == self.Guard:
+                    break
+                board[r][currC] = self.Guarded
+
+            for r in range(currR + 1, ROW):
+                if board[r][currC] == self.Wall or board[r][currC] == self.Guard:
+                    break
+                board[r][currC] = self.Guarded
+
+            for c in range(currC - 1, -1, -1):
+                if board[currR][c] == self.Wall or board[currR][c] == self.Guard:
+                    break
+                board[currR][c] = self.Guarded
+
+            for c in range(currC + 1, COL):
+                if board[currR][c] == self.Wall or board[currR][c] == self.Guard:
+                    break
+                board[currR][c] = self.Guarded
+
+        return sum([board[i].count(1) for i in range(ROW)])
+
+
+m = 4
+n = 6
+guards = [[0, 0], [1, 1], [2, 3]]
+walls = [[0, 1], [2, 2], [1, 4]]
+print(Solution().countUnguarded(m, n, guards, walls))
+
+m = 3
+n = 3
+guards = [[1, 1]]
+walls = [[0, 1], [1, 0], [2, 1], [1, 2]]
+print(Solution().countUnguarded(m, n, guards, walls))