// Program to test solutions to problem #9 on the cse142a final, autumn 2014.
// Fill in your solution to combineSublists, then compile and run the program.

import java.util.*;

public class FinalTest9 {
    public static int[] combineSublists(int[] list1, int[] list2, int start,
                                        int stop) {
        // fill in your solution here
        // you can also rename the parameters above
    }

    // this is the sample solution
    public static int[] combineSublists2(int[] list1, int[] list2, int start,
                                         int stop) {
        int sublistLength = stop - start;
        int[] result = new int[2 * sublistLength];
        for (int i = start; i < stop; i++) {
            result[i - start] = list1[i];
            result[i - start + sublistLength] = list2[i];
        }
        return result;
    }

    private static int count, failCount;

    public static final int ERRORS_MAX = 10;

    public static void main(String[] args) {
        for (int i = 1; i < 10; i++) {
            test(i, 2 * i - 1);
        }
        test(0, 5);
        test(1, 5);
        test(2, 5);

        if (failCount == 0) {
            System.out.println("passed all " + count + " tests");
        } else {
            System.out.println("failed " + failCount + " of " + count +
                               " tests");
        }
    }

    public static void test(int len1, int len2) {
        Random r = new Random();
        int[] list1 = new int[len1];
        int[] list2 = new int[len2];
        for (int i = 0; i < len1; i++) {
            list1[i] = r.nextInt(31) - 15;
        }
        for (int i = 0; i < len2; i++) {
            list2[i] = r.nextInt(31) - 15;
        }
        test(list1, list2);
        test(list2, list1);
    }


    public static void test(int[] list1, int[] list2) {
        int[] copy1 = Arrays.copyOf(list1, list1.length);
        int[] copy2 = Arrays.copyOf(list2, list2.length);
        int len = Math.min(list1.length, list2.length);
        for (int i = 0; i <= len; i++) {
            for (int j = i; j <= len; j++) {
                count++;
                int[] result1 = combineSublists2(list1, list2, i, j);
                int[] result2 = null;
                RuntimeException except = null;
                boolean fail = false;
                try {
                    result2 = combineSublists(list1, list2, i, j);
                } catch (RuntimeException e) {
                    except = e;
                    fail = true;
                }
                if (!Arrays.equals(result1, result2) ||
                    !Arrays.equals(list1, copy1) ||
                    !Arrays.equals(list2, copy2)) {
                    fail = true;
                }
                if (fail) {
                    System.out.println("failed with:");
                    System.out.println("    list1     = " + 
                                       Arrays.toString(copy1));
                    System.out.println("    list2     = " + 
                                       Arrays.toString(copy2));
                    System.out.println("    start     = " + i);
                    System.out.println("    stop      = " + j);
                    System.out.println("    correct   = " + 
                                       Arrays.toString(result1));
                    if (except == null) {
                        System.out.println("    theirs    = " + 
                                           Arrays.toString(result2));
                    } else {
                        int line = except.getStackTrace()[0].getLineNumber();
                        System.out.println("    threw " + except +
                                           " at line #" + line);
                    }
                    if (!Arrays.equals(list1, copy1)) {
                        System.out.println("    list1 now = " + 
                                           Arrays.toString(list1));
                    }
                    if (!Arrays.equals(list2, copy2)) {
                        System.out.println("    list2 now = " + 
                                           Arrays.toString(list2));
                    }
                    failCount++;
                    if (failCount > ERRORS_MAX) {
                        System.out.println("exceeds " + ERRORS_MAX + " errors");
                        System.out.println("with " + count + " correct");
                        System.exit(0);
                    }
                }
            }
        }
    }
}