题目描述

输入一个链表，按链表从尾到头的顺序返回一个 Array

测试用例

用例：

• 输入：[ 1, 2, 3, 4, 5 ]
• 输出：[ 5, 4, 3, 2, 1 ]

思路

遍历链表，通过unshift方法往数组的头部插入

代码实现

// 输入

var __readline = require("readline-sync");
__readline.setDefaultOptions({ prompt: "" });
var readline = __readline.prompt;

// 链表数据结构
function ListNode(val, next) {
  this.val = val == undefined ? 0 : val;
  this.next = next == undefined ? null : next;
}


// 输入链表

console.log("请输入链表: ");
let arr = readline().split(",").map(Number);
console.log("链表的数组表示形式为: ", arr);

// 把输入的数组形式转化为链表
let dummyHead = new ListNode();
let p = dummyHead;

for(let i = 0; i < arr.length; i ++){
  p.next = new ListNode(arr[i]);
  p = p.next;
}
console.log("dummyHead: ", dummyHead.next);
// 从头到尾打印链表
function tailToHead (head){
  let res = [];
  let cur = head;
  while(cur != null){
    res.unshift(cur.val);
    cur = cur.next;
  }
  return res;
}

let res = tailToHead(dummyHead.next);
console.log("结果为: ", res);