Remove Duplicates from Sorted List

基本的链表操作，只需一次遍历即可

    ListNode *deleteDuplicates(ListNode *head) {
        if(!head)
            return NULL;
        ListNode *cur, *next;
        cur = head;
        while(cur){
            next = cur->next;
            while(next){
                if(next->val != cur->val)
                    break;
                next = next->next;
            }
            cur->next = next;
            cur = cur->next;
        }
        return head;
    }