// Program to test solutions to problem #2 on the cse143 midterm, summer 2022.
// Fill in your solution to startsWith, then compile and run the program.

import java.util.*;

public class Test2 {

    public static boolean startsWith(String s1, String s2) {
        // fill in your solution here   
        // you can also rename the parameters above
    } 
    
    // this is the sample solution
    public static boolean startsWith2(String s1, String s2) {
        if (s2.length() == 0) {
            return true;
        } else if (s1.length() == 0) {
            return false;
        } else {
            return s1.charAt(0) == s2.charAt(0) &&
                startsWith2(s1.substring(1), s2.substring(1));
        }
    }

    public static void main(String[] args) {
        testHelper("Washington", "Wash");
        testHelper("Washington", "Washed");
        testHelper("hello", "he");
        testHelper("hello", "hen");
        testHelper("this", "t");
        testHelper("the", "");
        testHelper("", "the");
        testHelper("him", "HIM");
        testHelper("he", ".");
        testHelper("<*>!!", "<*>");
        testHelper("s", "she");
        testHelper("this", "that");
        testHelper("tom", "Tom");
        testHelper("hello", "hel");
        testHelper("this", "that");
        testHelper("Wash", "Washington");

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

    private static int testCount;
    private static int failCount;

    public static void testHelper(String s1, String s2) {
        test(s1, s2);
        test(s2, s1);
    }

    public static void test(String s1, String s2) {
        System.out.println("startsWith(\"" + s1 + "\", \"" + s2 + "\")");
        boolean expected = startsWith2(s1, s2);
        System.out.println("\texpected: " + expected);

        boolean fail = false;
        try {
            boolean actual = startsWith(s1, s2);
            if (expected != actual) {
                System.out.println("\tyour answer: " + actual);
                fail = true;
            }
        } catch (RuntimeException e) {
            int line = e.getStackTrace()[0].getLineNumber();
            System.out.println("\tthrew " + e + " at line #" + line);
            fail = true;
        }
        testCount++;
        if (fail) {
            System.out.println("failed");
            failCount++;
        } else {
            System.out.println("passed");
        }
        System.out.println();
    }
}