// Program to test solutions to problem #9 on the cse142a final, autumn 2016.
// Fill in your solution to collapse, then compile and run the program.

import java.util.*;

public class FinalTest9 {
    public static int[] collapse(int[] list) {
        // fill in your solution here
        // you can also rename the parameters above
    }

    // this is the sample solution
    public static int[] collapse2(int[] list) {
        int size = list.length / 2;
        if (list.length % 2 == 1) {
            size++;
        }
        int[] result = new int[size];
        for (int i = 0; i < list.length / 2; i++) {
            result[i] = list[i * 2] + list[i * 2 + 1];
        }
        if (list.length % 2 == 1) {
            result[result.length - 1] = list[list.length - 1];
        }
        return result;
    }

    private static int testCount, failCount;

    public static void main(String[] args) {
        test(0);
        for (int i = 1; i <= 15; i++) {
            for (int j = 0; j < 3; j++) {
                test(i);
            }
        }

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

    public static void test(int n) {
        int[] list = new int[n];
        Random r = new Random();
        for (int i = 0; i < n; i++) {
            list[i] = r.nextInt(19) - 9;
        }
        System.out.println("testing   " + Arrays.toString(list));
        int[] copy = Arrays.copyOf(list, list.length);
        testCount++;
        int[] result1 = collapse2(list);
        System.out.println("correct = " + Arrays.toString(result1));
        int[] result2 = null;
        RuntimeException except = null;
        boolean fail = false;
        try {
            result2 = collapse(list);
        } catch (RuntimeException e) {
            except = e;
            fail = true;
        }
        if (!Arrays.equals(result1, result2) || !Arrays.equals(list, copy)) {
            fail = true;
        }
        if (fail) {
            if (!Arrays.equals(result1, result2)) {
                if (except == null) {
                    System.out.println("yours   = " + Arrays.toString(result2));
                } else {
                    int line = except.getStackTrace()[0].getLineNumber();
                    System.out.println("threw " + except + " at line#" + line);
                }
            }
            if (!Arrays.equals(list, copy)) {
                System.out.println("array now = " + Arrays.toString(list));
            }
            failCount++;
            System.out.println("failed");
        } else {
            System.out.println("passed");
        }
        System.out.println();
    }
}