Create 1926-NearestExitFromEntranceInMaze.py

Author: Jiezhi

src/1926-NearestExitFromEntranceInMaze.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+"""
+CREATED AT: 2022-11-21
+
+URL: https://leetcode.com/problems/nearest-exit-from-entrance-in-maze/?envType=study-plan&id=graph-i
+
+GITHUB: https://github.com/Jiezhi/myleetcode
+
+FileName: 1926-NearestExitFromEntranceInMaze
+
+Difficulty: Medium
+
+Desc: 
+
+Tag: 
+
+See: 
+
+"""
+from tool import *
+
+
+class Solution:
+    def nearestExit(self, maze: List[List[str]], entrance: List[int]) -> int:
+        """
+        Runtime: 968 ms, faster than 82.11%
+        Memory Usage: 14.4 MB, less than 86.37%
+
+        maze.length == m
+        maze[i].length == n
+        1 <= m, n <= 100
+        maze[i][j] is either '.' or '+'.
+        entrance.length == 2
+        0 <= entrancerow < m
+        0 <= entrancecol < n
+        entrance will always be an empty cell.
+        """
+        m, n = len(maze), len(maze[0])
+        dirs = [(1, 0), (-1, 0), (0, 1), (0, -1)]
+        maze[entrance[0]][entrance[1]] = '+'
+        dq = deque([(entrance[0], entrance[1], 0)])
+        while dq:
+            x, y, step = dq.popleft()
+            if (x == 0 or x == m - 1 or y == 0 or y == n - 1) and step != 0:
+                return step
+            for dx, dy in dirs:
+                nx, ny = x + dx, y + dy
+                if not 0 <= nx < m or not 0 <= ny < n or maze[nx][ny] == '+':
+                    continue
+                maze[nx][ny] = '+'
+                dq.append((nx, ny, step + 1))
+        return -1
+
+
+def test():
+    assert Solution().nearestExit(maze=[["+", "+", ".", "+"], [".", ".", ".", "+"], ["+", "+", "+", "."]],
+                                  entrance=[1, 2]) == 1
+    assert Solution().nearestExit(maze=[["+", "+", "+"], [".", ".", "."], ["+", "+", "+"]], entrance=[1, 0]) == 2
+    assert Solution().nearestExit(maze=[[".", "+"]], entrance=[0, 0]) == -1
+
+
+if __name__ == '__main__':
+    test()