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链表用js实现

2026-03-01 14:13:53JavaScript

链表的基本概念

链表是一种线性数据结构，由一系列节点组成，每个节点包含数据和一个指向下一个节点的指针（或引用）。与数组不同，链表在内存中是非连续存储的，插入和删除操作更高效，但随机访问性能较差。

单链表的实现

以下是单链表的 JavaScript 实现，包含常用操作（插入、删除、查找等）：

class ListNode {
  constructor(data) {
    this.data = data;
    this.next = null;
  }
}

class LinkedList {
  constructor() {
    this.head = null;
    this.size = 0;
  }

  // 在链表末尾添加节点
  append(data) {
    const newNode = new ListNode(data);
    if (!this.head) {
      this.head = newNode;
    } else {
      let current = this.head;
      while (current.next) {
        current = current.next;
      }
      current.next = newNode;
    }
    this.size++;
  }

  // 在指定位置插入节点
  insertAt(data, index) {
    if (index < 0 || index > this.size) return false;
    const newNode = new ListNode(data);
    if (index === 0) {
      newNode.next = this.head;
      this.head = newNode;
    } else {
      let current = this.head;
      let prev = null;
      let i = 0;
      while (i < index) {
        prev = current;
        current = current.next;
        i++;
      }
      newNode.next = current;
      prev.next = newNode;
    }
    this.size++;
    return true;
  }

  // 删除指定位置的节点
  removeAt(index) {
    if (index < 0 || index >= this.size) return null;
    let removedNode;
    if (index === 0) {
      removedNode = this.head;
      this.head = this.head.next;
    } else {
      let current = this.head;
      let prev = null;
      let i = 0;
      while (i < index) {
        prev = current;
        current = current.next;
        i++;
      }
      removedNode = current;
      prev.next = current.next;
    }
    this.size--;
    return removedNode.data;
  }

  // 查找节点数据
  getAt(index) {
    if (index < 0 || index >= this.size) return null;
    let current = this.head;
    let i = 0;
    while (i < index) {
      current = current.next;
      i++;
    }
    return current.data;
  }

  // 打印链表数据
  print() {
    let current = this.head;
    const result = [];
    while (current) {
      result.push(current.data);
      current = current.next;
    }
    console.log(result.join(" -> "));
  }
}

使用示例

const list = new LinkedList();
list.append(10);
list.append(20);
list.append(30);
list.insertAt(15, 1);
list.print(); // 输出: 10 -> 15 -> 20 -> 30
list.removeAt(2);
list.print(); // 输出: 10 -> 15 -> 30
console.log(list.getAt(1)); // 输出: 15

双向链表的实现

双向链表的节点包含指向前驱和后继的指针，以下是一个简单实现：

链表用js实现

class DoublyListNode {
  constructor(data) {
    this.data = data;
    this.prev = null;
    this.next = null;
  }
}

class DoublyLinkedList {
  constructor() {
    this.head = null;
    this.tail = null;
    this.size = 0;
  }

  // 在末尾添加节点
  append(data) {
    const newNode = new DoublyListNode(data);
    if (!this.head) {
      this.head = newNode;
      this.tail = newNode;
    } else {
      newNode.prev = this.tail;
      this.tail.next = newNode;
      this.tail = newNode;
    }
    this.size++;
  }
}