// Program to test solutions to problem #3 on the cse143 midterm, fall 2012.
// There is a different method for each subproblem.


public class Test3 {
    public static void main(String[] args) {
        problem1();
        problem2();
        problem3();
    }

    public static void problem1() {
        ListNode p = new ListNode(1, new ListNode(2));
        ListNode q = null;
        System.out.println("before:");
        System.out.println(text(p, "p"));
        System.out.println(text(q, "q"));

        // this is the sample solution--replace with your code to test
        q = p.next;
        p.next = null;

        System.out.println("after:");
        String text1 = text(p, "p");
        String text2 = text(q, "q");
        System.out.println(text1);
        System.out.println(text2);

        if (text1.equals(" p->[1]") && text2.equals(" q->[2]"))
            System.out.println("PASSED");
        else
            System.out.println("FAILED");
        System.out.println();
    }
    public static void problem2() {
        ListNode p = new ListNode(1, new ListNode(2));
        ListNode q = null;
        System.out.println("before:");
        System.out.println(text(p, "p"));
        System.out.println(text(q, "q"));

        // this is the sample solution--replace with your code to test
        q = p;
        p = p.next;
        q.next = null;

        System.out.println("after:");
        String text1 = text(p, "p");
        String text2 = text(q, "q");
        System.out.println(text1);
        System.out.println(text2);

        if (text1.equals(" p->[2]") && text2.equals(" q->[1]"))
            System.out.println("PASSED");
        else
            System.out.println("FAILED");
        System.out.println();
    }

    public static void problem3() {
        ListNode p = new ListNode(1, new ListNode(2, new ListNode(3)));
        ListNode q = new ListNode(4, new ListNode(5));
        System.out.println("before:");
        System.out.println(text(p, "p"));
        System.out.println(text(q, "q"));

        // this is the sample solution--replace with your code to test
        ListNode temp = q;
        q = p.next.next;
        p.next.next = temp.next;
        temp.next = p.next;
        p.next = temp;

        System.out.println("after:");
        String text1 = text(p, "p");
        String text2 = text(q, "q");
        System.out.println(text1);
        System.out.println(text2);

        if (text1.equals(" p->[1]->[4]->[2]->[5]") && text2.equals(" q->[3]"))
            System.out.println("PASSED");
        else
            System.out.println("FAILED");
        System.out.println();
    }

    public static String text(ListNode p, String text) {
        String result = " " + text;
        for (int i = 0; i < 5; i++) {
            if (p != null) {
                result += "->[" + p.data + "]";
                p = p.next;
            }
        }
        if (p != null)
            result += "...";
        return result;
    }
}

class ListNode {
    public int data;       // data stored in this node
    public ListNode next;  // link to next node in the list

    // post: constructs a node with data 0 and null link
    public ListNode() {
	this(0, null);
    }

    // post: constructs a node with given data and null link
    public ListNode(int data) {
	this(data, null);
    }

    // post: constructs a node with given data and given link
    public ListNode(int data, ListNode next) {
	this.data = data;
	this.next = next;
    }
}