hdu 3555 Bomb 数位DP

#include<cstdio>
#include<cstring>
#include<algorithm>
#define ll __int64
using namespace std;
int bit[20];
ll dp[20][3];
ll dfs(int pos,int h,bool f)
{
if(pos==-1) return h==2;
if(!f&&dp[pos][h]!=-1) return dp[pos][h];
ll ans=0;
int e=f?bit[pos]:9;
for(int i=0;i<=e;i++){
int ha=h;
if(h==1&&i==9) ha=2;
if(h==1&&i!=9) ha=0;
if(h!=2&&i==4) ha=1;
ans+=dfs(pos-1,ha,f&&(i==bit[pos]));
}
if(!f) dp[pos][h]=ans;
return ans;
}
ll cal(ll n)
{
int m=0;
while(n){
bit[m++]=n%10;
n/=10;
}
return dfs(m-1,0,1);
}
int main()
{
ll n;
int t;
memset(dp,-1,sizeof(dp));
scanf("%d",&t);
while(t--){
scanf("%I64d",&n);
printf("%I64d\n",cal(n));
}
}