hdu 3652 B-number 数位DP

#include<cstdio>
#include<cstring>
int bit[10],dp[10][10][13][2];
int dfs(int pos,int pre,int mod,bool h,bool inf)
{
if(pos==-1) return h&&!mod;
if(!inf&&dp[pos][pre][mod][h]!=-1) return dp[pos][pre][mod][h];
int i,ans=0;
int e=inf?bit[pos]:9;
for(i=0;i<=e;i++){
if(pre==1&&i==3) ans+=dfs(pos-1,i,(mod*10+i)%13,1,inf&&(i==bit[pos]));
else ans+=dfs(pos-1,i,(mod*10+i)%13,h,inf&&(i==bit[pos]));
}
if(!inf) dp[pos][pre][mod][h]=ans;
return ans;
}
int cal(int n)
{
int pos=0;
while(n){
bit[pos++]=n%10;
n/=10;
}
return dfs(pos-1,0,0,0,1);
}
int main()
{
int n,ans,m,k;
memset(dp,-1,sizeof(dp));
while(scanf("%d",&n)!=EOF){
printf("%d\n",cal(n));
}
}