algo/javascript/09_queue/CircularQueueBasedOnLinkedList.js
2019-08-05 17:25:11 +08:00

71 lines
1.6 KiB
JavaScript

/**
* 基于链表实现的循环队列。
*
* Author: nameczz
*/
class Node {
constructor(element) {
this.element = element
this.next = null
}
}
class CircularQueue {
constructor() {
this.head = null
this.tail = null
}
enqueue(value) {
if (this.head === null) {
this.head = new Node(value)
this.head.next = this.head
this.tail = this.head
} else {
const flag = this.head === this.tail
this.tail.next = new Node(value)
this.tail.next.next = this.head
this.tail = this.tail.next
if (flag) {
this.head.next = this.tail
}
}
}
dequeue() {
if(this.head == null) return -1
if (this.head === this.tail) {
const value = this.head.element
this.head = null
return value
} else {
const value = this.head.element
this.head = this.head.next
this.tail.next = this.head
return value
}
}
display() {
let res = 0
console.log('-------获取dequeue元素------')
while (res !== -1) {
res = this.dequeue()
console.log(res)
}
}
}
// Test
const newCircularQueue = new CircularQueue()
// 插入元素
newCircularQueue.enqueue(1)
newCircularQueue.enqueue(2)
newCircularQueue.enqueue(3)
// 获取元素
newCircularQueue.display()
newCircularQueue.enqueue(1)
newCircularQueue.display()
// exports.CreatedStack = StackBasedLinkedList