HDU 3652 B-number

#include <cstdio>
#include <cmath>
#include <cstring>
#include <string>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <stack>
#include <map>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <utility>
using namespace std;

#define rep(i,j,k) for (int i=j;i<=k;i++)
#define Rrep(i,j,k) for (int i=j;i>=k;i--)

#define Clean(x,y) memset(x,y,sizeof(x))
#define LL long long
#define ULL unsigned long long
#define inf 0x7fffffff
#define mod %100000007

int dp[12][13][3]; // dp[i][yu][id]  id = 0:不以1结尾   id = 1:以1结尾  id = 2:含"13"
int digit[12];

int dfs( int k , int yu , int id , bool flag )
{
if ( k == 0 ) return ( yu == 0 && id == 2 ); //可以被13整除且含有13就计数一次
if ( !flag && dp[k][yu][id]!=-1 ) return dp[k][yu][id]; //是否之前求过这个子问题
int ed = flag?digit[k]:9;
int ans = 0;
rep(i,0,ed)
{
int next_yu = (yu*10 + i)%13;
int next_id = id;
if ( id == 0 && i == 1 ) next_id = 1;
if ( id == 1 && i != 1 ) next_id = 0;
if ( id == 1 && i == 3 ) next_id = 2;
ans+=dfs( k-1 , next_yu , next_id , flag && i == ed );
}
if ( !flag ) dp[k][yu][id] = ans;
return ans;
}

int cal(int x)
{
int len = 0;
while( x )
{
digit[++len] = x % 10;
x /= 10;
}
return dfs( len , 0 , 0 , 1 );
}

int main()
{
Clean(dp,-1);
int x;
while(cin>>x)
{
printf("%d\n",cal(x));
}

return 0;
}