Homework3.java

/* Homework3.java */

public class Homework3 {

    /**
     *  smoosh() takes an array of ints.  On completion the array contains
     *  the same numbers, but wherever the array had two or more consecutive
     *  duplicate numbers, they are replaced by one copy of the number.  Hence,
     *  after smoosh() is done, no two consecutive numbers in the array are the
     *  same.
     *
     *  Any unused elements at the end of the array are set to -1.
     *
     *  For example, if the input array is [ 0 0 0 0 1 1 0 0 0 3 3 3 1 1 0 ],
     *  it reads [ 0 1 0 3 1 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 ] after smoosh()
     *  completes.
     *
     *  @param ints the input array.
     **/

    public static void smoosh(int[] ints) {
        int n = ints.length;
        int i = 1, j = 1;
        while(i < n){
            if(ints[i] != ints[i - 1]){
                ints[j] = ints[i];
                j++;
            }
            i++;
        }
        for(int k = j; k < n; k++){
            ints[k] = -1;
        }
    }

    /**
     *  stringInts() converts an array of ints to a String.
     *  @return a String representation of the array.
     **/

    private static String stringInts(int[] ints) {
        String s = "[  ";
        for (int i = 0; i < ints.length; i++) {
            s = s + Integer.toString(ints[i]) + "  ";
        }
        return s + "]";
    }

    /**
     *  main() runs test cases on your smoosh and squish methods.  Prints summary
     *  information on basic operations and halts with an error (and a stack
     *  trace) if any of the tests fail.
     **/

    public static void main(String[] args) {
        String result;
        int i;


        System.out.println("Let's smoosh arrays!\n");

        int[] test1 = {3, 7, 7, 7, 4, 5, 5, 2, 0, 8, 8, 8, 8, 5};
        System.out.println("smooshing " + stringInts(test1) + ":");
        smoosh(test1);
        result = stringInts(test1);
        System.out.println(result);
        TestHelper.verify(result.equals(
                "[  3  7  4  5  2  0  8  5  -1  -1  -1  -1  -1  -1  ]"),
                "BAD SMOOSH!!!  No cookie.");

        int[] test2 = {6, 6, 6, 6, 6, 3, 6, 3, 6, 3, 3, 3, 3, 3, 3};
        System.out.println("smooshing " + stringInts(test2) + ":");
        smoosh(test2);
        result = stringInts(test2);
        System.out.println(result);
        TestHelper.verify(result.equals(
                "[  6  3  6  3  6  3  -1  -1  -1  -1  -1  -1  -1  -1  -1  ]"),
                "BAD SMOOSH!!!  No cookie.");

        int[] test3 = {4, 4, 4, 4, 4};
        System.out.println("smooshing " + stringInts(test3) + ":");
        smoosh(test3);
        result = stringInts(test3);
        System.out.println(result);
        TestHelper.verify(result.equals("[  4  -1  -1  -1  -1  ]"),
                "BAD SMOOSH!!!  No cookie.");

        int[] test4 = {0, 1, 2, 3, 4, 5, 6};
        System.out.println("smooshing " + stringInts(test4) + ":");
        smoosh(test4);
        result = stringInts(test4);
        System.out.println(result);
        TestHelper.verify(result.equals("[  0  1  2  3  4  5  6  ]"),
                "BAD SMOOSH!!!  No cookie.");


        System.out.println("\nLet's squish linked lists!\n");

        int[] test5 = {3, 7, 7, 7, 4, 5, 5, 2, 0, 8, 8, 8, 8, 5};
        SList list5 = new SList();
        for (i = 0; i < test5.length; i++) {
            list5.insertEnd(new Integer(test5[i]));
        }
        System.out.println("squishing " + list5.toString() + ":");
        list5.squish();
        result = list5.toString();
        System.out.println(result);
        TestHelper.verify(result.equals("[  3  7  4  5  2  0  8  5  ]"),
                "BAD SQUISH!!!  No biscuit.");

        int[] test6 = {6, 6, 6, 6, 6, 3, 6, 3, 6, 3, 3, 3, 3, 3, 3};
        SList list6 = new SList();
        for (i = 0; i < test6.length; i++) {
            list6.insertEnd(new Integer(test6[i]));
        }
        System.out.println("squishing " + list6.toString() + ":");
        list6.squish();
        result = list6.toString();
        System.out.println(result);
        TestHelper.verify(result.equals("[  6  3  6  3  6  3  ]"),
                "BAD SQUISH!!!  No biscuit.");

        int[] test7 = {4, 4, 4, 4, 4};
        SList list7 = new SList();
        for (i = 0; i < test7.length; i++) {
            list7.insertEnd(new Integer(test7[i]));
        }
        System.out.println("squishing " + list7.toString() + ":");
        list7.squish();
        result = list7.toString();
        System.out.println(result);
        TestHelper.verify(result.equals("[  4  ]"),
                "BAD SQUISH!!!  No biscuit.");

        int[] test8 = {0, 1, 2, 3, 4, 5, 6};
        SList list8 = new SList();
        for (i = 0; i < test8.length; i++) {
            list8.insertEnd(new Integer(test8[i]));
        }
        System.out.println("squishing " + list8.toString() + ":");
        list8.squish();
        result = list8.toString();
        System.out.println(result);
        TestHelper.verify(result.equals("[  0  1  2  3  4  5  6  ]"),
                "BAD SQUISH!!!  No biscuit.");

        SList list9 = new SList();
        System.out.println("squishing " + list9.toString() + ":");
        list9.squish();
        result = list9.toString();
        System.out.println(result);
        TestHelper.verify(result.equals("[  ]"),
                "BAD SQUISH!!!  No biscuit.");


        System.out.println("\nLet's twin linked lists!\n");

        System.out.println("twinning " + list6.toString() + ":");
        list6.twin();
        result = list6.toString();
        System.out.println(result);
        TestHelper.verify(result.equals(
                "[  6  6  3  3  6  6  3  3  6  6  3  3  ]"),
                "BAD TWIN!!!  No gravy.");

        System.out.println("twinning " + list7.toString() + ":");
        list7.twin();
        result = list7.toString();
        System.out.println(result);
        TestHelper.verify(result.equals("[  4  4  ]"),
                "BAD TWIN!!!  No gravy.");

        System.out.println("twinning " + list9.toString() + ":");
        list9.twin();
        result = list9.toString();
        System.out.println(result);
        TestHelper.verify(result.equals("[  ]"),
                "BAD TWIN!!!  No gravy.");
    }

}