Question

题目内容

解题思路

迭代。

代码实现

/**
 * Definition for singly-linked list.
 * class ListNode {
 *     val: number
 *     next: ListNode | null
 *     constructor(val?: number, next?: ListNode | null) {
 *         this.val = (val===undefined ? 0 : val)
 *         this.next = (next===undefined ? null : next)
 *     }
 * }
 */

const reverseList = (head: ListNode | null): ListNode | null => {
  let prev: ListNode | null = null;
  let curr: ListNode | null = head;
  while (curr) {
    const next: ListNode | null = curr.next;
    curr.next = prev;
    prev = curr;
    curr = next;
  }
  return prev;
};