841 python3 add BFS solution.md

problems/0841.钥匙和房间.md

@@ -324,7 +324,7 @@ class Solution {
 ### python3
 
 ```python
-
+# 深度搜索优先
 class Solution:
     def dfs(self, key: int, rooms: List[List[int]]  , visited : List[bool] ) :
         if visited[key] :
@@ -346,6 +346,31 @@ class Solution:
                 return False
         return True
 
+# 广度搜索优先
+class Solution:
+    def canVisitAllRooms(self, rooms: List[List[int]]) -> bool:
+        visited = [False] * len(rooms)
+        self.bfs(rooms, 0, visited)
+        
+        for room in visited:
+            if room == False:
+                return False
+        
+        return True
+    
+    def bfs(self, rooms, index, visited):
+        q = collections.deque()
+        q.append(index)
+
+        visited[0] = True
+
+        while len(q) != 0:
+            index = q.popleft()
+            for nextIndex in rooms[index]:
+                if visited[nextIndex] == False:
+                    q.append(nextIndex)
+                    visited[nextIndex] = True
+
 ```