HDU2089[不要62]--数位DP

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn=25;
int n,m,ans,len,f[maxn][10],a[maxn];
inline int Read()
{
int res=0; char ch=getchar();
while (ch<'0'||ch>'9') ch=getchar();
while (ch>='0'&&ch<='9') res=res*10+ch-48,ch=getchar();
return res;
}
int Dfs(int x,int las,bool pd)
{
if (x>len) return 1;
if (!pd&&f[x][las]) return f[x][las];
int MAX=9; if (pd) MAX=a[x]; f[x][las]=0;
for (int i=0; i<=MAX; i++)
if ((las!=6&&i!=4)||(las==6&&i!=2&&i!=4)) f[x][las]+=Dfs(x+1,i,pd&(i==a[x]));
return f[x][las];
}
void Work()
{
memset(f,0,sizeof(f));
a[0]=len=0;int x=n-1;
while (x) a[++len]=x%10,x/=10;
for (int i=1; i<=len/2; i++) swap(a[i],a[len-i+1]);
ans=Dfs(1,0,1);
memset(f,0,sizeof(f));
a[0]=len=0; x=m;
while (x) a[++len]=x%10,x/=10;
for (int i=1; i<=len/2; i++) swap(a[i],a[len-i+1]);
printf("%d\n",Dfs(1,0,1)-ans);
n=Read(); m=Read();
}
int main()
{
freopen("2089.in","r",stdin);
freopen("2089.out","w",stdout);
n=Read(); m=Read();
while (n||m) Work();
return 0;
}