3.5.java

3.5.java

//implement a MyQueue class which implements a queue using two stacks
public class MyQueue<T>{
	Stack<T> stackNew, stackOld;
	public MyQueue(){
		stackNew = new Stack<T>();
		stackOld = new Stack<T>();
	}
	public int size(){
		return stackNew.size() + stackOld.size();
	}
	public void add(T value){
		stackNew.push(value);
	}
	private void shiftStacks(){
		if(stackOld.isEmpty())
		{
			while(!stackNew.isEmpty())
				stackOld.push(stackNew.pop());
		}
	}
	public T peek(){
		shiftStacks();
		return stackOld.peek();
	}
	public T remove(){
		shiftStacks();
		return stackOld.pop();
	}
}