Queue_Implementation_Stack_Type1

"""
S1 -> S2
X -> S1
S2 -> S1
"""
class Queue:
    def __init__(self):
        self.OneStack = []
        self.TwoStack = []

    def Push(self, Val):
        while(self.OneStack):
            self.TwoStack.append(self.OneStack.pop())
        self.OneStack.append(Val)
        while(self.TwoStack):
            self.OneStack.append(self.TwoStack.pop())

    def Pop(self):
        print(self.OneStack.pop())

    def Top(self):
        print(self.OneStack[-1])

ObjQueue = Queue()
ObjQueue.Push(1)
ObjQueue.Push(2)
ObjQueue.Push(4)
ObjQueue.Pop()
ObjQueue.Top()