[HDU 3652] B-number

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 int dp[15][2][2][13],dig[15];
 4 int dfs(int dep,int one,int thirteen,int yu,int flag){
 5     if(!dep){
 6         if(thirteen)return yu?1:0;
 7         else return 1;
 8     }
 9     if(!flag&&dp[dep][one][thirteen][yu]!=-1)return dp[dep][one][thirteen][yu];
10     int lim=flag?dig[dep]:9;
11     int ans=0;
12     for(int i=0;i<=lim;i++){
13         if(one&&i==3)ans+=dfs(dep-1,i==1,1,(yu*10+i)%13,flag&(i==lim));
14         else ans+=dfs(dep-1,i==1,thirteen,(yu*10+i)%13,flag&(i==lim));
15     }
16     if(!flag)dp[dep][one][thirteen][yu]=ans;
17     return ans;
18 }
19 int solve(int x){
20     int dd=0;
21     while(x)dig[++dd]=x%10,x/=10;
22     return dfs(dd,0,0,0,1);
23 }
24 int main(){
25     memset(dp,-1,sizeof(dp));
26     int A;
27     while(scanf("%d",&A)!=EOF)
28         printf("%d\n",A-solve(A)+1);//
29     return 0;
30 }