[Leetcode]237. Delete Node in a Linked List -David_Lin

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, the linked list should become 1 -> 2 -> 4 after calling your function.

法一：思路是：从node 节点开始，把后面节点的值赋给前面的节点，直到到表尾；

 /**
  * Definition for singly-linked list.
  * public class ListNode {
  *     int val;
  *     ListNode next;
  *     ListNode(int x) { val = x; }
  * }
  */
 class Solution {
     public void deleteNode(ListNode node) {
         ListNode pos = node.next;
         if (pos==null)
             node=null;
         else {
             while (pos!=null){
                 node.val = pos.val;
                 pos = pos.next;
                 if (pos==null)
                     node.next = null;
                 else
                     node = node.next;
             }
         }
     }
 }

法二：将要删除节点后一个节点的值赋给要删除的节点，然后删除后一个节点。

 /**
  * Definition for singly-linked list.
  * public class ListNode {
  *     int val;
  *     ListNode next;
  *     ListNode(int x) { val = x; }
  * }
  */
 class Solution {
     public void deleteNode(ListNode node) {
         if(node.next==null){
            node=null;
            return;
         }
         node.val = node.next.val;
         node.next = node.next.next;
     }
 }