牛客网—剑指offer-用两个栈实现队列

import java.util.Stack;

/**
* Created by Administrator on 2017/3/1.
*/
public class Solution {
Stack<Integer> stack1=new Stack<Integer>();
Stack<Integer> stack2=new Stack<Integer>();

public void push(int node){
stack1.push(node);
}

public int pop(){
if(stack1.empty()&&stack2.empty()){
throw new RuntimeException("Queue is empty!");
}
if(stack2.empty()){
while(!stack1.empty()){
stack2.push(stack1.pop());
}

}

return stack2.pop();

}
}

/**
* Created by Administrator on 2017/3/1.
*/
public class MyTest {

public static void main(String[]  args) {
Solution myso = new Solution();
int[] a = {1, 2, 3, 4, 5, 6, 7, 8, 9};
System.out.print("length: "+a.length);
for (int i = 0; i < a.length; i++) {
myso.push(a[i]);
System.out.print("input: "+a[i]);

}
for(int i=0;i<a.length;i++){
System.out.println(myso.pop());
}

}
}