public class Main
{

    final static int NO_OF_CHARS = 256;

    static int max_distinct_char(String str, int n) {

        int count[] = new int[NO_OF_CHARS];

        for (int i = 0; i < n; i++) {
            count[str.charAt(i)]++;
        }

        int max_distinct = 0;
        for (int i = 0; i < NO_OF_CHARS; i++) {
            if (count[i] != 0) {
                max_distinct++;
            }
        }

        return max_distinct;
    }

    static int smallesteSubstr_maxDistictChar(String str) {

        int n = str.length();
        int max_distinct = max_distinct_char(str, n);
        int minl = n;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {

                String subs = null;
                if(i<j)
                    subs = str.substring(i, j);
                else
                    subs = str.substring(j, i);
                int subs_lenght = subs.length();
                int sub_distinct_char = max_distinct_char(subs, subs_lenght);

                if (subs_lenght < minl && max_distinct == sub_distinct_char) {
                    minl = subs_lenght;
                }
            }
        }
        return minl;
    }
    static public void main(String[] args) {
        String str = "SKADOOSHLUNATIC";

        int len = smallesteSubstr_maxDistictChar(str);
        System.out.println(" The length of the smallest substring"
                + " consisting of maximum distinct "
                + "characters : "+len);
    }
}