思路：把要删除的节点的下一个节点的值放到被删除的节点处,删除下一个节点.

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