Remove Duplicates from Sorted List

Topic:

Given a sorted linked list, delete all duplicates such this each element appear only once.

For example,
Given 1->1->2 , return 1->2 .
Given 1->1->2->3->3 , return 1->2->3 .

Analytical:

Started because of negligence two times runtime error situation, for the list of problems is generally the following situation

1. Null->next

2. The pointer is NULL, also with the pointer val,p = Null,p->val

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* Deleteduplicates (listnode*head) { A         if(head = = NULL | | head->next = =NULL) -             returnhead; -ListNode *p =head; the          while(p->next) -         { -             if(P->val = = p->next->val) -P->next = p->next->Next; +             Else -p = p->Next; +         } A         returnhead; at     } -};

Remove Duplicates from Sorted List