Any way to somehow reverse (-x)-1

general
1

Here’s a programming challenge I have been baffled on:

public class CrackTheCode {

public static void main(String[] args) {
    // Test the masher
    String testString = "One Team, One Goal, One Web.";
    if (Masher.unmash(Masher.mash(testString)).equals(testString)) {
        System.out.println("OK");
    } else {
        System.out.println("Error");
    }
}


static class Masher {

    static String mash(String s) {
        byte[] bytes = s.getBytes();
        byte[] mashed = new byte[bytes.length];
        for (int i = 0; i < bytes.length; i++) {
            mashed[i] = (byte) ~bytes[i];
        }
        return new String(mashed);
    }

    static String unmash(String s) {
        //TODO
        return null;
    }
}

}

2

Take another 1’s complement?

-((-x) - 1) - 1 = x + 1 - 1 = x

Or did I not understand your question?

3

static class Masher {

static  String mash(String s) {
    byte[] bytes = s.getBytes();
    byte[] mashed = new byte[bytes.length];
    for (int i = 0; i < bytes.length; i++) {
        mashed[i] = (byte) ~bytes[i];
    }
	char[] chars=new char[mashed.length];
	for (int i = 0; i < mashed.length; i++) {
        chars[i] = (char)mashed[i];
	}
    return new String(chars);
}

static String unmash(String s) {
    char[] chars = s.toCharArray();
	byte[] unmashed=new byte[chars.length];
    for (int i = 0; i < chars.length; i++) {
        unmashed[i] =(byte)~(byte)(chars[i]);
    }
    return new String(unmashed);
}

}

the string typecasting was messing up with negative values in bytes…however worked fine this way