#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<bitset>
#define ls k<<1
#define rs k<<1|1
using namespace std;
const int MAXN=1000001;
inline void read(int &n)
{
char c=‘+‘;int x=0;bool flag=0;
while(c<‘0‘||c>‘9‘){c=getchar();if(c==‘-‘)flag=1;}
while(c>=‘0‘&&c<=‘9‘){x=x*10+(c-48);c=getchar();}
n=flag==1?-x:x;
}
int dp[21][3];
int n,m;
int a[21];
int pos;
int dfs(int pos,int pre,int how,bool lim)
{
if(pos==-1) return 1;
if(!lim&&dp[pos][how]!=-1)
return dp[pos][how];
int up=lim?a[pos]:9;
int tmp=0;
for(int i=0;i<=up;i++)
{
if(i==4)continue;
if(pre==6&&i==2)continue;
tmp+=dfs(pos-1,i,i==6,lim&&i==a[pos]);
}
if(!lim)dp[pos][how]=tmp;
return tmp;
}
int work(int num)
{
pos=0;
while(num)
{
a[pos++]=num%10;
num=num/10;
}
return dfs(pos-1,-1,0,1);
}
int main()
{
memset(dp,-1,sizeof(dp));
while(scanf("%d%d",&n,&m))
{
if(n==0&&m==0)break;
printf("%d\n",work(m)-work(n-1));
}
return 0;
}
原文:http://www.cnblogs.com/zwfymqz/p/7308830.html