一个stack 实现 queue

public class Queue<Element>
{
private Stack<Element> s1 = new Stack<Element>();
private Stack<Element> s2 = new Stack<Element>();

public void enqueue(Element e){
s1.push(e);
return;
}
public Element dequeue()
{
if(s2.isEmpty())
{
while(!s1.isEmpty())
{
Element e = s1.pop();
s2.push(e);
}
}
return s2.pop();
}

}

 

 

insert(E value) 
{ 
stack.push(value); 
} 

E remove() 
{ 
E top = stack.pop(); 
if(stack.isEmpty()) 
return top; 
else 
{ 
E result = remove(); 
stack.push(top); 
return result; 
} 
}