HDU P2089

 1 #include<cstdio>
 2 #include<cmath>
 3 using namespace std;
 4 int f[8][10];
 5 
 6 int work(int);
 7 
 8 int main()
 9 {
10     int n,m,ans=0,i,j,k;
11     f[0][0]=1;
12     for(k=1;k<=7;k++)
13     for(i=0;i<=9;i++)
14         if(i!=4)
15             for(j=0;j<=9;j++)
16                 if(i!=6||j!=2)
17                     f[k][i]+=f[k-1][j];
18     while(scanf("%d%d",&n,&m)==2&&m||n){
19         ans=work(m);
20         ans=ans-work(n-1);
21         if(m<n)ans=0;
22         printf("%d\n",ans);
23     }
24 }
25 
26 int work(int x)
27 {
28     int i,j,k,y=0,sum=0,z=0;
29     if(x==0)return 1;
30     int len=(int)log10(x)+1;
31     int mod=1;
32     for(i=1;i<=len-1;i++)
33         mod*=10;
34     for(k=len;k>=1;k--){
35         y=x/mod;
36         x%=mod;
37         if(z!=4)
38             for(i=0;i<y;i++)
39                 if(z!=6||i!=2)
40                     sum+=f[k][i];
41         if(k==1&&y!=4&&z!=4&&(z!=6||y!=2))
42             sum++;
43         if(y==4||(z==6&&y==2))break;
44         z=y;
45         mod/=10;
46     }
47     return sum;
48 }