ENCODE A STRING USING LZW ALGORITHM

import java.util.*;

public class LZW {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.println("ENTER THE STRING YOU NEED TO ENCODE : ");
        String s = new String(sc.next());
        String d[] = new String[500];
        for (int i = 0; i < 256; i++)
            d[i] = new String((char) (i) + "");
        int j = 0;
        int l = 256;
        String prefix = new String(s.charAt(j++) + "");
        String ch = "";
        int flag = 0;
        while (j < s.length()) {
            ch = new String(s.charAt(j++) + "");
            flag = 0;
            for (int k = 0; k < l; k++) {
                if ((prefix + ch).equals(d[k].toString())) {
                    flag = 1;
                    break;
                }
            }
            if (flag == 1)
                prefix = prefix + ch;
            else {
                d[l] = prefix + ch;
                for (int m = 0; m < l; m++)
                    if (prefix.equals(d[m].toString())) {
                        System.out.print("<" + m + ">");
                        break;
                    }
                prefix = ch;
                l++;
                flag = 0;
            }

        }
        if (flag == 1) {
            for (int q = 0; q < l; q++)
                if ((prefix).toString().equals(d[q].toString()))
                    System.out.print("<" + q + ">");
        } else {
            for (int x = 0; x < l; x++)
                if (ch.toString().equals(d[x].toString()))
                    System.out.println("<" + x + ">");
        }
    }

}
/*
OUTPUT:
ENTER THE STRING YOU NEED TO ENCODE :
BABCABABA
<66><65><66><67><257><260>
*/