[剑指offer]用两个栈实现队列
思路:
进行队列的push操作时,直接将元素push进stack1即可,Pop操作先判断stack2中有无元素,如果有直接pop,没有就将stack1中元素pop并push进stack2中,再进行pop操作即可
实现:
import java.util.Stack;
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(stack2.isEmpty())
while(!stack1.isEmpty()){
int temp=stack1.pop();
stack2.push(temp);
}
return stack2.pop();
}
}