Reverse a singly linked list.
Example:
Input: 1->2->3->4->5->NULL Output: 5->4->3->2->1->NULL
Follow up:
A linked list can be reversed either iteratively or recursively. Could you implement both?
Explanation:
Iterative Method
- Initialize three pointers prev as NULL, curr as head and next as NULL.
- Iterate trough the linked list. In loop, do following.
// Before changing next of current,
// store next node
next = curr->next// Now change next of current
// This is where actual reversing happens
curr->next = prev// Move prev and curr one step forward
prev = curr
curr = next
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ class Solution { public ListNode reverseList(ListNode head) { ListNode prev =null, curr = head, next = null; while(curr!=null){ next = curr.next; curr.next = prev; prev = curr; curr = next; } return prev; } }
(Easy) Reverse linked list LeetCode
原文：https://www.cnblogs.com/codingyangmao/p/11419928.html