leetcode237~Delete Node in a Linked List

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.

删除一个节点，这题确实很简单，但乍一看可能没啥思路。只给出一个节点，而且要删除这个节点，常见的是找到前驱，然后让前驱的next指向要删除节点的下一个节点即可。这里头节点都没给出，显然不能这样做。
一个节点只能获取到下一个节点的信息，故采用了值替换。

public void deleteNode(ListNode node) {
        if(node.next==null) {
            return;
        }
       node.val = node.next.val;
       node.next = node.next.next;
    }