RoomItems = "a aa b"
DirtyRoom = "aaba"
RoomItems = sorted(RoomItems.split(" "), key=len)
def Yarr(RoomItems, DirtyRoom):
for Item in RoomItems:
if all(char in DirtyRoom[0:len(Item)] for char in Item):
print Item, DirtyRoom[0:len(Item)]
RoomItems.remove(Item)
DirtyRoom = DirtyRoom.replace(DirtyRoom[0:len(Item)],"",1)+DirtyRoom[0:len(Item)]
Yarr(RoomItems, DirtyRoom)
Yarr(RoomItems, DirtyRoom)