leetcode:203 Remove Linked List Elements－每日編程第四十題

Remove Linked List Elements

Total Accepted: 44897 Total Submissions: 165785 Difficulty: Easy

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

/**
 * 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* p=head;
        while(p!=NULL&&p->val==val){
            head=p->next;
            //delete p;
            p=head;
        } 
        if(head==NULL){
            return head;
        }
        while(p->next!=NULL){
            if(p->next->val==val){
                ListNode* temp=p->next;
                p->next=temp->next;
                delete temp;
            }else{
                p=p->next;
            }
        }
        return head;
    }
};