Project 6 Hashing Stuff

To get you started on Project 6, here is the basic code to read the checkme.txt file. It reads words, converts to upper case, and strips extraneous punctuation.

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.Scanner;

public class Main {

    public static String removeNonLetDig(String s) {
        int b = 0, e = s.length()-1;

        // Trim from the beginning
        while (b <= e && !Character.isLetterOrDigit(s.charAt(b)))
            b++;

        // Trim from the end
        while (e >= b && !Character.isLetterOrDigit(s.charAt(e)))
            e--;

        if (b <= e)
            return s.substring(b,e + 1);
        else
            return null;
    }

    public static void main(String[] args) throws FileNotFoundException {

        Scanner inFile = new Scanner(new FileReader("checkme.txt"));

        while (inFile.hasNext()) {
            String word = inFile.next().toUpperCase();
            String stripped = removeNonLetDig(word);
            System.out.printf("Original %-15s Modified %-15s%n", word, stripped);
        }
        inFile.close();
    }
}

The output shows that null is possible. Remember that this indicates that no letters (or digits) remained after processing. This is not a misspelled word; it's not a word at all.

Original -*-             Modified null           
Original OUTLINE         Modified OUTLINE        
Original -*-             Modified null           
Original THIS            Modified THIS           
Original DIRECTORY       Modified DIRECTORY      
Original CONTAINS        Modified CONTAINS       
Original BISON           Modified BISON          
Original SKELETONS:      Modified SKELETONS
...