// Program to test solutions to problem #2 on the cse143 midterm, winter 2018.
// Fill in your solution to groupChars, then compile and run the program.

import java.util.*;

public class Test2 {
    public static String groupChars(String s) {
        // fill in your solution here
        // you can also rename the parameter above
    }

    // this is the sample solution
    public static String groupChars2(String s) {
        if (s.length() == 0) {
            return "*";
        } else if (s.length() < 3) {
            return "[" + s + "]";
        } else {
            int last = s.length() - 1;
            return "(" + s.charAt(0) + groupChars(s.substring(1, last)) + 
                s.charAt(last) + ")";
        }
    }

    private static int testCount;
    private static int failCount;

    public static final int ERRORS_MAX = 25;

    public static void main(String[] args) {
        String[] data = {"", "a", "5", " ", "ab", ", ", "abc", "a b", "abcde",
                         "a b ", "12345", "1 3 5", " 2 4 ", "123456",
                         "1234567", "12345678", "123456789", "a", "the",
                         "rain", "in", "Spain", "falls", "mainly",
                         "recursively!"};
        for (String s : data) {
            test(s);
        }

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

    public static void test(String s) {
        System.out.println("testing groupChars(\"" + s + "\")");
        String result1 = groupChars2(s);
        boolean fail = false;
        try {
            String result2 = groupChars(s);
            if (!result1.equals(result2)) {
                fail = true;
                System.out.println("result should be \"" + result1 +
                                   "\", yours = \"" + result2 + "\"");
            }
        } catch (RuntimeException e) {
            int line = e.getStackTrace()[1].getLineNumber();
            System.out.println("threw " + e + " at line #" + line);
            fail = true;
        }
        testCount++;
        if (fail) {
            System.out.println("failed");
            failCount++;
            if (failCount > ERRORS_MAX) {
                System.out.println("exceeds " + ERRORS_MAX + " errors");
                System.out.println("with " + testCount + " correct");
                System.exit(0);
            }
        } else {
            System.out.println("passed");
        }
        System.out.println();
    }
}