Implement a queue using two stacks

Problem

Implement a queue using two stacks.
Example input:
enqueue(1)
enqueue(2)
enqueue(3)
Example output:
1
2
3

Solution

This solution is in C#. Our A.I. can create solutions in multiple languages.

kayakane

using System;
using System.Collections.Generic;

namespace InterviewPreperationGuide.Core.CrackingTheCodingInterview.c3q6 {
    public class Solution {
        public void Init () {
            Console.WriteLine ();
        }
    }

    public class MyQueue<T> {
        private Stack<T> stackNewestOnTop = new Stack<T> ();
        private Stack<T> stackOldestOnTop = new Stack<T> ();

        public void Enqueue (T value) {
            stackNewestOnTop.Push (value);
        }

        public T Peek () {
            ShiftStacks ();
            return stackOldestOnTop.Peek ();
        }

        public T Dequeue () {
            ShiftStacks ();
            return stackOldestOnTop.Pop ();
        }

        private void ShiftStacks () {
            if (stackOldestOnTop.Count == 0) {
                while (stackNewestOnTop.Count > 0) {
                    stackOldestOnTop.Push (stackNewestOnTop.Pop ());
                } }
        }
    }
}