题解 | 用两个栈实现队列

package main

var stack1 []int
var stack2 []int

func Push(node int) {
	stack1 = append(stack1, node)
}

func Pop() int {
	for len(stack1) > 0 {
		tmp := stack1[0]
		stack1 = stack1[1:] // stack1 pop
		stack2 = append(stack2, tmp) // stack2 push
	}

	res := stack2[0]
	stack2 = stack2[1:] // stack2 pop

	for len(stack2) > 0 {
		tmp := stack2[0]
		stack2 = stack2[1:] // stack2 pop
		stack1 = append(stack1, tmp) // stack1 push
	}
	return res
}