Create 286-Walls-and-Gates.py

Author: neetcode-gh

286-Walls-and-Gates.py

@@ -0,0 +1,27 @@
+class Solution:
+    """
+    @param rooms: m x n 2D grid
+    @return: nothing
+    """
+    def walls_and_gates(self, rooms: List[List[int]]):
+        ROWS, COLS = len(rooms), len(rooms[0])
+        visit = set()
+        q = deque()
+
+        def addRooms(r, c):
+            if (min(r, c) < 0 or r == ROWS or c == COLS or
+                (r, c) in visit or rooms[r][c] == -1):
+                return
+            visit.add((r, c))
+            q.append([r, c])
+        
+        dist = 0
+        while q:
+            for i in range(len(q)):
+                r, c = q.popleft()
+                rooms[r][c] = dist
+                addRooms(r + 1, c)
+                addRooms(r - 1, c)
+                addRooms(r, c + 1)
+                addRooms(r, c - 1)
+            dist += 1