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

 

1 /** 2  * Definition for singly-linked list. 3  * struct ListNode { 4  *     int val; 5  *     struct ListNode *next; 6  * }; 7  */ 8 struct ListNode* removeElements(struct ListNode* head, int val) 9 {10         if(head==NULL)11         return NULL;12     13     if(head->next==NULL&&head->val==val)14     {15         return NULL;16     }17 18     if(head->next==NULL&&head->val!=val)19     {20         return head;21     }22 23 24     25     struct ListNode *p=head;26     27     while(p->val==val&&p->next!=NULL)28     {29         p=p->next;30     }31     32     if(p->val==val)33     {34         return NULL;35     }36     37     38     head=p;39     40     if(p->next==NULL)41     {42         return head;43     }44 45     while(p->next->next!=NULL)46     {47         if(p->next->val==val)48         {49             p->next=p->next->next;50             continue;51         }52         p=p->next;53     }54     55     if(p->next->val==val)56     {57         p->next=NULL;58     }59     60     return head;61 }