Java implementation of the Brute Force Algorithm

Java implementation of the Brute Force Algorithm

  September 04, 2022    Nikos Siatras

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This is my single threaded implementation of the Brute Force algorithm for Java. I build this algorithm purely for scientific purposes.

A brief code explanation:

The fCharList array holds the characters involved in the algorithm. You can add or remove characters according to your needs.

The StartBruteForce method starts a brute force word generation. The length parameter of this method determins how many characters a word can have.

The OnBruteForceWordGenerated  is called for every Brute-Force generated word.

Example #1: For a length of 4 the StartBruteForce method  will generate the following words "aaaa","aaab","aaac".....,"zzzz"

Example #2: For a length of 8 the StartBruteForce method  will generate the following words "aaaaaaaa","aaaaaaab","aaaaaaac".....,"zzzzzzzz"

/**
 *
 * @author Nikos Siatras
 */
public class BruteForce
{

    private static final char[] fCharList =
    {
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
    };

    public static void main(String[] args)
    {
        for (int i = 1; i < 17; i++)
        {
            StartBruteForce(i);
        }
    }

    /**
     * This method is called every time a new word is generated
     *
     * @param word is the brute force generated word
     */
    private static void OnBruteForceWordGenerated(String word)
    {
        System.out.println(word);
    }

    /**
     * Start a new Brute Force
     *
     * @param length is the words length (how many characters a word can have)
     */
    private static void StartBruteForce(int length)
    {
        StringBuffer sb = new StringBuffer(length);
        char currentChar = fCharList[0];

        for (int i = 1; i <= length; i++)
        {
            sb.append(currentChar);
        }

        ChangeCharacters(0, sb, length);
    }

    private static StringBuffer ChangeCharacters(int pos, StringBuffer sb, int length)
    {
        for (int i = 0; i <= fCharList.length - 1; i++)
        {
            sb.setCharAt(pos, fCharList[i]);
            if (pos == length - 1)
            {
                // Write the Brute Force generated word.
                OnBruteForceWordGenerated(sb.toString());
            }
            else
            {
                ChangeCharacters(pos + 1, sb, length);
            }
        }

        return sb;
    }
}