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

删除链表中指定值，找到其前一个节点即可，将 next 指向下一个节点即可。

设置一个哑节点来防止头节点被删除造成无法返回新链表。

/** * 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) {        if (head == nullptr)            return 0;        ListNode* dummy = new ListNode(0);        dummy->next = head;        ListNode* cur = dummy;        while (cur->next) {            if (cur->next->val == val) {                cur->next = cur->next->next;            }            else {                cur = cur->next;            }        }        return dummy->next;    }};// 26 ms