题目来源：https://leetcode.cn/leetbook/read/queue-stack/kzlb5/

package main

import "fmt"

// 设计循环队列 ，一个长度为N的循环队列
func main() {

	a := Constructor(3)
	fmt.Println(a.EnQueue(1))
	fmt.Println(a.EnQueue(2))
	fmt.Println(a.EnQueue(3))
	fmt.Println(a.EnQueue(4))
	fmt.Println(a.Rear())
	fmt.Println(a.IsFull())
	fmt.Println(a.DeQueue())
	fmt.Println(a.EnQueue(4))
	fmt.Println(a.Rear())

}

func Constructor(k int) MyCircularQueue {
	return MyCircularQueue{
		len:  k,
		list: make([]int, k),
		str:  -1,
		end:  -1,
	}
}

type MyCircularQueue struct {
	len      int
	list     []int
	str, end int
}

func (q *MyCircularQueue) EnQueue(value int) bool {

	if q.IsFull() {
		return false
	}

	if q.IsEmpty() {
		q.str = 0
	}

	q.end = (q.end + 1) % q.len
	q.list[q.end] = value
	return true
}

func (q *MyCircularQueue) DeQueue() bool {

	if q.IsEmpty() {
		return false
	}

	if q.str == q.end {
		q.str = -1
		q.end = -1
		return true
	}

	q.str = (q.str + 1) % q.len

	return true
}

func (q *MyCircularQueue) Front() int {

	if q.IsEmpty() {
		return -1
	}

	return q.list[q.str]
}

func (q *MyCircularQueue) Rear() int {

	if q.IsEmpty() {
		return -1
	}

	return q.list[q.end]
}

func (q *MyCircularQueue) IsEmpty() bool {
	if q.end == -1 && q.str == -1 {
		return true
	}
	return false
}

func (q *MyCircularQueue) IsFull() bool {
	return (q.end+1)%q.len == q.str
}

我有N台文件服务器，需要实现负载均衡

// 简单的轮训算法
current = (current + 1) % n