[Leetcode] 203. Remove Linked List Elements 解题报告

题目：

Remove all elements from a linked list of integers that have value val.

Example
Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6
Return: 1 --> 2 --> 3 --> 4 --> 5

思路：

Easy级别的题目，无须赘述。只是重要的事情再强调一下：引入虚拟头结点可以大大简化思路和代码！！！

代码：

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public:    ListNode* removeElements(ListNode* head, int val) {        ListNode pre_head(0);        pre_head.next = head;        ListNode* node = &pre_head;        while (node->next != NULL) {            if (node->next->val == val) {                ListNode* temp = node->next;                node->next = temp->next;                delete temp;            }            else {                node = node->next;            }        }        return pre_head.next;    }};