hdu2089数位dp

[L,R]中数字不含有4或62的个数。

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StreamTokenizer;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.NavigableSet;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;
import java.util.SortedSet;
import java.util.Stack;
import java.util.StringTokenizer;
import java.util.TreeSet;

public class Main {

    public static void main(String[] args) throws IOException{
           StreamTokenizer cin = new StreamTokenizer(new BufferedInputStream(System.in)); 
           InputReader in = new InputReader(System.in)  ;
           PrintWriter out = new PrintWriter(System.out) ;

           while(true){
                int l = in.nextInt() ;
                int r = in.nextInt() ;
                if(l==0 && r==0) break ;
                new Task().solve(l, r , out) ;
           }
           out.flush() ; 
    }

}


class  Task{

       static int  dp[][] = new int[10][10] ;
       static{
                for(int i = 0 ; i < 10 ; i++)  Arrays.fill(dp[i], -1);
       } 
       static int[]  bit = new int[10] ;
       static int  len ;

       int  dfs(int pos , int pre , boolean end){
            if(pos == -1) return 1 ;
            if(!end && dp[pos][pre] != -1) return dp[pos][pre] ;
            int d = end ? bit[pos] : 9 ;
            int sum = 0 ;
            for(int i = 0 ; i <= d ; i++){
                 if(i == 4) continue ;
                 if(pre == 6 && i == 2) continue ;
                 sum += dfs(pos-1 , i , end && i == d) ;
            }
            if(!end) dp[pos][pre] = sum ;
            return sum ;
       }

       int  answer(int n){
            len = 0 ;
            while(n > 0){
                bit[len++] = n % 10 ;
                n /= 10 ;
            }          
            return dfs(len-1 , 0 , true)  ;
       }

       public void solve(int l , int r , PrintWriter out) throws IOException{
              out.println(answer(r) - answer(l-1)) ;
       }
}

class   InputReader{
        public BufferedReader  reader;
        public StringTokenizer  tokenizer;

        public InputReader(InputStream stream){
               reader = new BufferedReader(new InputStreamReader(stream), 32768) ;
               tokenizer = null ;
        }

        public String next(){
               while(tokenizer == null || ! tokenizer.hasMoreTokens()){
                   try{
                        tokenizer = new StringTokenizer(reader.readLine());
                   }catch (IOException e){
                        throw new RuntimeException(e);
                   }
               }
               return tokenizer.nextToken();  
        }

        public int  nextInt(){
               return Integer.parseInt(next());
        }

        public long nextLong(){
               return Long.parseLong(next());
        }

        public double nextDouble(){
               return  Double.parseDouble(next());
        }

}