UVA - 12527 - Different Digits

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuffer sb = new StringBuffer("");
        String m = "";
        int arr[]=new int[5001];
        for(int i=1;i<5001;i++){
            arr[i]=arr[i-1];
            if(valid(i+"")){
                arr[i]++;
            }
        }
        while((m=br.readLine())!=null){
           String[]str=m.split(" ");
           int x=Integer.parseInt(str[0]);
           int y=Integer.parseInt(str[1]);
           sb.append(arr[y]-arr[x-1]).append("\n");
        }
        System.out.print(sb);
    }
  
    static boolean valid(String x){
        int[]arr =new int[10];
        for(int i=0;i<x.length();i++){
            arr[x.charAt(i)-48]++;
            if(arr[x.charAt(i)-48]>1)
                return false;
        }
        return true;
    }
}