SimpleQueue.ts

/**
 * 使用链表实现简单队列
 */
class SimpleQueue<T> {
  private head: LinkedNode<T> | null = null
  private tail: LinkedNode<T> | null = null

  /**
   * 入队,插入队尾
   * @param value
   */
  public enqueue(value: T) {
    if (!this.tail) {
      this.head = this.tail = new LinkedNode<T>(value)
    } else {
      const newNode = new LinkedNode<T>(value)
      this.tail.next = newNode
      this.tail = newNode
    }
  }

  /**
   * 出队,在队头删除
   */
  public dequeue(): T | null {
    if (!this.head) return null
    const value = this.head.value
    this.head = this.head.next
    return value
  }

  public printAll(): string {
    let p = this.head
    let res = ''
    while (p) {
      res = `${res} ${p.value}`
      p = p.next
    }
    return res
  }
}

/**
 * 单向链表
 */
class LinkedNode<T> {
  value: T
  next: LinkedNode<T> | null

  constructor(value: T, next: LinkedNode<T> | null = null) {
    this.value = value
    this.next = next
  }
}

const queue = new SimpleQueue()
queue.enqueue(1)
queue.enqueue(2)
queue.enqueue(3)
queue.dequeue()
queue.dequeue()
console.log(queue.printAll())