【HDU3652】B-number

Problem

http://acm.hdu.edu.cn/showproblem.php?pid=3652

Solution

同Bomb，多记一个sum为%13后的余数

CODE

/*
 * @key word:digit DP
 * @tesed on:HDU 3652 0ms
 * @Author: lhq 
 * @Date: 2017-08-16 19:42:38 
 * @Last Modified by:   lhq 
 * @Last Modified time: 2017-08-16 19:42:38 
 */
 #include<iostream>
 #include<cstdio>
 #include<cstring>
 using namespace std;
 #define ll long long
 int a[20];
 ll dp[20][2][2][15],n;

 ll dfs(int len,bool sta,bool pre,int sum,bool limit)
 {
     if (len==0) return (sta && !sum)?1:0;
     if (!limit && dp[len][sta][pre][sum]!=-1) return dp[len][sta][pre][sum];
     int up=limit?a[len]:9;
     ll ans=0;
     for (int i=0;i<=up;i++)
         ans+=dfs(len-1,sta || pre && i==3,i==1,(sum*10+i)%13,limit && i==up);
     if (!limit) dp[len][sta][pre][sum]=ans;
     return ans;
 }
 ll solve(ll x)
 {
     int len=0;
     while (x)
     {
         a[++len]=x%10;
         x/=10;
     }
     return dfs(len,false,false,0,true);
 }
 int main()
 {
     memset(dp,-1,sizeof(dp));
     while (scanf("%lld",&n)!=EOF)
         printf("%lld\n",solve(n));
     return 0;
 }