/*
 * Kyle Pierce
 * CSE 143
 *
 * Class LinkedIntList can be used to store an ordered sequence of integers
 */
public class LinkedIntList {
   private ListNode front;

   // Constructs an empty list
   public LinkedIntList() {
      front = null;
   }

   // post: constructs a new list with the values 
   //       [n, n-1, ..., 1, 0]
   public LinkedIntList(int n) {
      front = null;
      for (int i = 0; i <= n; i++) {
         front = new ListNode(n - i, front);
      } 
   }

   // post: appends the given value to the end of the list                                       
   public void add(int value) {   
      if (front == null) {                                                    
         front = new ListNode(value);                                     
      } else {                               
         ListNode current = front;                                                   
         while (current.next != null) {                                                   
            current = current.next;                                 
         }                             
         current.next = new ListNode(value);                                              
      }                               
   }                                 

   // pre: 0 <= index <= size 
   // post: inserts the given value at the given index, shifting subsequent
   //       values right                                       
   public void add(int index, int value) {                                              
      if (index == 0) {                                             
         front = new ListNode(value, front);                                              
      } else {                                                    
         for (int i = 0; i < index - 1; i++) {
            current = current.next;
         }                 
         current.next = new ListNode(value, current.next);                                 
      }                                              
   }

   // pre : list is in sorted (non-decreasing) order
   // post: given value inserted into list so as to preserve sorted order
   public void addSorted(int value) {
      if (front == null || front.data > value) {
         front = new ListNode(value, front);
      } else {
         ListNode current = front;
         while (current.next != null && current.next.data < value) {
            current = current.next;
         }
         current.next = new ListNode(value, current.next);
      }
   }

   // pre : list is in sorted (non-decreasing) order
   // post: given value inserted into list so as to preserve sorted order
   public void addSorted2(int value) {
      if (front == null || front.data > value) {
         front = new ListNode(value, front);
      } else {
         ListNode prev = front;
         ListNode current = front.next;
         while (current != null && current.data < value) {
            prev = prev.next;
            current = current.next;
         }
         prev.next = new ListNode(value, current);
      }
   }
}