LeeCode-Remove Duplicates from Sorted List

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

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

 /**
  * Definition for singly-linked list.
  * struct ListNode {
  *     int val;
  *     struct ListNode *next;
  * };
  */
 struct ListNode* deleteDuplicates(struct ListNode* head)
 {
     if(head==NULL)
         return NULL;

     if(head!=NULL&&head->next==NULL)
         return head;

     if(head->next->next==NULL)
     {
         if(head->val==head->next->val)
         {
             head->next==NULL;
             return head->next;
         }

         if(head->val!=head->next->val)
         {
             return head;
         }
     }

      struct ListNode* p;
      p=head;

      int count=;
      while(p!=NULL)
      {
          p=p->next;
          count++;
      }

      int *array;
      array=(int *)malloc(count*sizeof(int));

      p=head;
      int i=;
      while(p!=NULL)
      {
          array[i]=p->val;
          i++;
          p=p->next;
      }

      p=head;
      for(i=;i<count-;i++)
      {
         if(array[i]!=array[i+])
         {
             p->val=    array[i];
             p=p->next;
         }
      }

      p->val=array[count-];
      p->next=NULL;

      return head;
 }