Leetcode Remove Linked List Elements

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

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

Credits:
Special thanks to @mithmatt for adding this problem and creating all test cases.

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It's not hard to feel. is to traverse the good, so far for the list of many problems can only traverse a method bar, can not avoid to traverse. The point to note on this topic is: (1) If the deleted points are in the head what to do, the final must be returned empty. (2) Remove the tail node should be noted. There are three kinds of points: the head point, the tail point, the middle point.

1 /**2 * Definition for singly-linked list.3 * struct ListNode {4 * int val;5 * ListNode *next;6 * ListNode (int x): Val (x), Next (NULL) {}7  * };8  */9 classSolution {Ten  Public: Onelistnode* removeelements (listnode* head,intval) { A         if(Head==null)returnhead; -listnode* p,*Q; -          while(head->val==val) { the             if(Head->next==null) {head=head->next;returnhead;} -Head=head->Next; -         } -P=head,q=head->Next; +          while(q!=NULL) { -             if(q->val==val) { +                 if(q->next==null) p->next=NULL; AP->next=q->Next; atQ=q->next;} -             Else{p=Q; -Q=q->Next; -             } -         } -         returnhead; in     } -};

Leetcode Remove Linked List Elements