w3.q13

ListNode* rotateRight(ListNode* head, int k) {
        if(head == NULL){
            return NULL;
        }
        
        if(head->next == NULL){
            return head;
        }
        
        if(k == 0){
            return head;
        }
        
        ListNode *temp = head;
        ListNode *slow = NULL;
        
        int len = 0;
        while(temp != NULL){
            len++;
            temp = temp->next;
        }
        
        if(k%len == 0){
            return head;
        }
        
        if(k > len){
            k = k%len;
        }
        
        temp = head;
        int i = 0;
        while(temp != NULL){
            if(i == k){
                if(slow == NULL){
                    slow = head;
                }
            }
            
            if(slow != NULL){
                slow = slow->next;
            }
            
            temp = temp->next;
            i++;
        }
        
        
        
        ListNode *new_head = slow;
        temp = head;
        
        while(temp->next != slow){
            temp = temp->next;
        }
        
        temp->next = NULL;
        
        temp = slow;
        while(temp->next != NULL){
            temp = temp->next;
        }
        
        temp->next = head;
        return new_head;
    }
};