841: add a solution in Python3

Author: KennyTzeng

841.Keys_and_Rooms/main.py

@@ -0,0 +1,28 @@
+class Solution:
+    def canVisitAllRooms(self, rooms):
+        """
+        :type rooms: List[List[int]]
+        :rtype: bool
+        """
+        
+        locks = [1] + [0] * (len(rooms) - 1)
+        keys = set()
+
+        for key in rooms[0]:
+            keys.add(key)
+        found = True
+
+        while found:
+            found = False
+            for i in range(len(rooms)):
+                if locks[i] == 0:
+                    if i in keys:
+                        locks[i] = 1
+                        for key in rooms[i]:
+                            keys.add(key)
+                        found = True
+
+        if 0 in locks:
+            return False
+        else:
+            return True