LintCode:删除列表中的元素

#LintCode:删除列表中的元素

/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */
class Solution {
public:
    /** * @param head a ListNode * @param val an integer * @return a ListNode */
    ListNode *removeElements(ListNode *head, int val) {
        // Write your code here
        if(head==NULL) return head;
        while(head->val==val){
            head = head->next;
            if(head==NULL) return NULL;
        }
        ListNode *p = head;
        while(p->next!=NULL){
            if(p->next->val == val){
                p->next = p->next->next;
            }
            else{
                p = p->next;
            }
        }
        return head;
    }
};