题解 | #用两个栈实现队列#
用两个栈实现队列
http://www.nowcoder.com/practice/54275ddae22f475981afa2244dd448c6
两个栈倒腾一下
进队列时,栈2非空就把栈2的挪到栈1里,进栈1
出队列时,栈1非空就把栈1的挪到栈2里,出栈2
import java.util.Stack; public class Solution { Stack<Integer> stack1 = new Stack<Integer>(); Stack<Integer> stack2 = new Stack<Integer>(); public void push(int node) { while(!stack2.isEmpty()){ stack1.push(stack2.pop()); } stack1.push(node); } public int pop() { while(!stack1.isEmpty()){ stack2.push(stack1.pop()); } return stack2.pop(); } }