148. 排序链表🔖链表🔖js初始化单链表

148. 排序链表

• https://leetcode-cn.com/problems/sort-list/

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @return {ListNode}
 */
var sortList = function(head) {
    if (head === null) return head
    let arr = []
    while (head !== null) {
        arr.push(head.val)
        head = head.next
    }
    let result = arr.sort((a, b) => {return a - b})
    let result_head = new ListNode(result[0], null)
    let test = result_head
    result.forEach((data, index) => {
        if (index !== 0) {
            let temp = new ListNode(data,null)
            test.next = temp
            test = temp
        }
    })
    return result_head
};

js初始化单链表

// 节点
class Node {
  constructor(value) {
    this.val = value
    this.next = null
  }
}

// 利用数组来初始化单链表
class NodeList {
  constructor(arr) {
    let head = new Node(arr.shift())
    let next = head
    arr.forEach(data => {
      next.next = new Node(data)
      next = next.next
    })
    return head
  }
}

let test = new NodeList([1, 2, 3, 4])
while (test !== null) {
  console.log(test.val)
  test = test.next
}