# 232. Implement Queue using Stacks

{% hint style="info" %}
straight forward, stack1 is the main stack, stack2 is the help stack. `In push()` and `peek()`, `pop` all elements of stack1 to stack2, and then `push` back to stack1.
{% endhint %}

{% tabs %}
{% tab title="Python" %}

```python
class MyQueue:

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.stack1 = []
        self.stack2 = []

    def push(self, x: int) -> None:
        """
        Push element x to the back of queue.
        """
        self.stack1.append(x)
        

    def pop(self) -> int:
        """
        Removes the element from in front of queue and returns that element.
        """
        while len(self.stack1) != 1:
            self.stack2.append(self.stack1.pop())
        tmp = self.stack1.pop()
        while len(self.stack2) != 0:
            self.stack1.append(self.stack2.pop())
        return tmp
        

    def peek(self) -> int:
        """
        Get the front element.
        """
        while len(self.stack1) != 1:
            self.stack2.append(self.stack1.pop())
        tmp = self.stack1.pop()
        self.stack1.append(tmp)
        while len(self.stack2) != 0:
            self.stack1.append(self.stack2.pop())
        return tmp       
        

    def empty(self) -> bool:
        """
        Returns whether the queue is empty.
        """
        return len(self.stack1) == 0


# Your MyQueue object will be instantiated and called as such:
# obj = MyQueue()
# obj.push(x)
# param_2 = obj.pop()
# param_3 = obj.peek()
# param_4 = obj.empty()
```

{% endtab %}
{% endtabs %}