237. 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.

思路：

　　先考虑特殊情况：（1）链表为空（2）只有一个节点 -- 都直接返回

　　普通情况：链表不为空，且后续节点也不为空

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
void deleteNode(struct ListNode* node) {
    if (!node)  //链表不为空
        return;
    else if (node->next){  //要删的节点还有后续节点
        node->val = node->next->val;
        node->next = node->next->next;
    }
    else  //其他情况，如列表不为空且要删除的是最后一个节点
        return;
}