Time: 27 ms (81.71%), Space: 18.7 MB (27.37%) - LeetHub

Author: hogan-tech

0505-the-maze-ii/0505-the-maze-ii.py

@@ -0,0 +1,47 @@
+# time complexity: O(m*n*log(m*n))
+# space complexity: O(m*n)
+from collections import defaultdict
+from heapq import heappop, heappush
+from typing import List
+
+
+class Solution:
+    def shortestDistance(self, maze: List[List[int]], start: List[int], destination: List[int]) -> int:
+        ROW = len(maze)
+        COL = len(maze[0])
+        visited = defaultdict(lambda: float('inf'))
+        minHp = [(0, start[0], start[1])]
+        visited[(start[0], start[1])] = 0
+        while minHp:
+            currDist, currR, currC = heappop(minHp)
+            if [currR, currC] == destination:
+                return currDist
+            for dR, dC in [(1, 0), (0, 1), (-1, 0), (0, -1)]:
+                nextR = currR
+                nextC = currC
+                nextDist = currDist
+                while 0 <= nextR + dR < ROW and 0 <= nextC + dC < COL and maze[nextR + dR][nextC + dC] == 0:
+                    nextR += dR
+                    nextC += dC
+                    nextDist += 1
+                if nextDist < visited[(nextR, nextC)]:
+                    heappush(minHp, (nextDist, nextR, nextC))
+                    visited[(nextR, nextC)] = nextDist
+        return -1
+
+
+maze = [[0, 0, 1, 0, 0], [0, 0, 0, 0, 0], [
+    0, 0, 0, 1, 0], [1, 1, 0, 1, 1], [0, 0, 0, 0, 0]]
+start = [0, 4]
+destination = [4, 4]
+print(Solution().shortestDistance(maze, start, destination))
+maze = [[0, 0, 1, 0, 0], [0, 0, 0, 0, 0], [
+    0, 0, 0, 1, 0], [1, 1, 0, 1, 1], [0, 0, 0, 0, 0]]
+start = [0, 4]
+destination = [3, 2]
+print(Solution().shortestDistance(maze, start, destination))
+maze = [[0, 0, 0, 0, 0], [1, 1, 0, 0, 1], [
+    0, 0, 0, 0, 0], [0, 1, 0, 0, 1], [0, 1, 0, 0, 0]]
+start = [4, 3]
+destination = [0, 1]
+print(Solution().shortestDistance(maze, start, destination))