《剑指offer》-用两个栈实现队列

import java.util.Stack;

public class CQueue {
public static Stack<Integer> stack1 = new Stack<Integer>();
public static Stack<Integer> stack2 = new Stack<Integer>();
public static void main(String[] args) {
// TODO Auto-generated method stub
CQueue c = new CQueue();
for(int i = 0; i < 5; i++){
c.appendTail(i);
c.printQueue();
}
for(int i = 0; i < 3; i++){
c.deleteHead();
c.printQueue();
}
}
public void printQueue(){//打印的是出队的顺序
Stack<Integer> tmp = new Stack<>();
while(!stack2.empty()){
tmp.push(stack2.pop());
System.out.print(tmp.peek() + " ");
}
while(!tmp.empty()){
stack2.push(tmp.pop());
}
while(!stack1.empty()){
tmp.push(stack1.pop());
}
while(!tmp.empty()){
stack1.push(tmp.pop());
System.out.print(stack1.peek() + " ");
}
System.out.println();
}
public void appendTail(Integer i){
stack1.push(i);
}
public int deleteHead(){
if(stack2.empty()){
while(!stack1.empty()){
Integer tmp = stack1.pop();
stack2.push(tmp);
}
}
if(stack2.empty()){
System.out.println("queue is empty");
}
Integer i = stack2.pop();
return i;
}
}