【hdu2089】不要62 [数位dp]

#include<iostream>
#include<cstdio>
#include<queue>
#include<cstring>
#include<cmath>
#include<stack>
#include<algorithm>
using namespace std;
#define ll long long
#define rg register
const int N=2000000000+5,pw=11,inf=0x3f3f3f3f,P=19650827;
ll a,b,x,y;
ll base[20],f[20][10];
//填了多少 当前
template <class t>void rd(t &x)
{
    x=0;int w=0;char ch=0;
    while(!isdigit(ch)) w|=ch==‘-‘,ch=getchar();
    while(isdigit(ch)) x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
    x=w?-x:x;
}

void pre(){
    for(int i=0;i<=9;++i) f[1][i]=(!(i==4));
    for(int i=2;i<=8;++i)
    for(int j=0;j<=9;++j){
        if(j==4) {f[i][j]=0;continue;}
        for(int k=0;k<=9;++k)
        if(!(k==4||j==6&&k==2)) f[i][j]+=f[i-1][k];
    }
    
}

ll solve(ll xx){
    ll p=0,num[20],sum=0;
//    for(p=0;p<=13;++p) if(base[p]>x) break;
    while(xx) num[++p]=xx%10,xx/=10;
    num[p+1]=0;
/*    for(int i=1;i<p;++i)
    for(int j=1;j<=9;++j) sum+=f[i][j];
    for(int i=1;i<num[p];++i) sum+=f[p][i];
    for(int i=p-1;i>0;--i){
           for(int j=0;j<num[i];++j)
           if(!(j==2&&num[i+1]==6)) sum+=f[i][j];
        if(num[i]==4||(num[i]==2&&num[i+1]==6)) break;
    }*/
    for(int i=p;i>0;--i){
        for(int j=0;j<num[i];++j)
           if(!(j==2&&num[i+1]==6)) sum+=f[i][j];
        if(num[i]==4||(num[i]==2&&num[i+1]==6)) break;
        
    }
    return sum;
}

int main()
{
    //freopen("in.txt","r",stdin);
    //freopen("nocows.out","w",stdout);
    pre();
/*   for(int i=1;i<=9;++i){
       printf("\n");
       for(int j=0;j<=9;++j) printf("%d ",f[i][j]);
   }*/
    while(scanf("%lld%lld",&a,&b)==2&&a&&b){
        printf("%lld\n",solve(b+1)-solve(a));
    } 
    return 0;
}