// Hunter Schafer, CSE 143
// This class represents a list of integers
public class LinkedIntList {
    private ListNode front;
    
    // Constructs an empty list
    public LinkedIntList() {
        front = null;
    }
    
    // Returns a String representation of this list 
    // surrounded by square brackets with the elements in order 
    // separated by commas.
    // Example: [1, 2, 3, 4]
    public String toString() {
        // commented out code is code for array
        
        // if (size == 0) {
        if (front == null) {
            return "[]";
        }
        // String result = "[" + elementData[0];
        String result = "[" + front.data;

        // int i = 1;
        ListNode current = front.next;
        // while (i < size) { 
        while (current != null) {
            // result += ", " + elementData[i];
            result += ", " + current.data;
            // i = i + 1;
            current = current.next;
        }
        result += "]";
        return result;
    }
    
    // Adds the given value to the end of this 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: Adds the given value at the given index, shifting subsequent 
    //       values to the right
    public void add(int index, int value) { 
        if (index == 0) {
            // Longer solution
            // ListNode temp = new ListNode(value);
            // temp.next = front;
            // front = temp
            
            // Shorter solution, both are fine
            front = new ListNode(value, front);
        } else {
            ListNode current = front;
            for (int i = 0; i < index - 1; i++) {
                current = current.next;
            }
            // Long solution, definitely works
            // ListNode temp = new ListNode(value);
            // temp.next = current.next;
            // current.next = temp;
            
            // Shorter solution, both are fine
            current.next = new ListNode(value, current.next);
        }
    }
}