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Lucky numbers

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 510		Accepted: 172

Description

John has recently arrived in Bucharest for the South Eastern European Regional Contest. John is famous for his theory of lucky numbers. That’s why all the contestants and spectators are very happy.

According to that theory 4 and 7 are lucky digits, and all the other digits are not lucky. A lucky number is a number that contains only lucky digits in decimal notation. A very lucky number is a number that can be expressed as a product of several lucky numbers.
A lucky number by itself is considered to be very lucky. For example, numbers 47, 49, 112 are very lucky.

Your task is to calculate the number of very lucky numbers that are not less than A and not greater than B. Of course, numbers A and B are given by John.

Input

The first line of the input contains a single integer T – a number of test cases. Each of the next T lines contains two integers separated by a single space – A and B.

Output

Output must contain T lines – answers for the test cases.

Sample Input

4
1 2
88 99
112 112
1 100

Sample Output

0
0
1
10

Hint

Constrains:

1 ≤ T ≤ 7777,

1 ≤ A ≤ B ≤ 1000000000000 (1012).

#include<iostream>
#include<algorithm>
#include<cstdio>
using namespace std;
const __int64 inf=1000000000000LL;
const int maxn=10002;
const int maxm=50000000;
int t,l,ll;
__int64 d[maxn],s[maxm],a,b;
void dfs(__int64 p,int step)
{
if(step>12) return;
d[l++]=p*10+4;
d[l++]=p*10+7;
dfs(p*10+4,step+1);
dfs(p*10+7,step+1);
}
void dfs1(__int64 p,int step)
{
if(step>=l)return;
if(d[step]>inf/p) return;
dfs1(p,step+1);
while(d[step]<=inf/p)
{
p*=d[step];
s[ll++]=p;
dfs1(p,step+1);
}
}
int main()
{
l=0,s[ll=1]=0;
dfs(0,1);
sort(d,d+l);
dfs1(1,0);
sort(s,s+ll);
int len=unique(s,s+ll)-s;
// cout<<"OK "<<l<<" "<<ll<<endl;
scanf("%d",&t);
while(t--)
{
scanf("%I64d%I64d",&a,&b);
int id1=upper_bound(s,s+len,a-1)-s;
int id2=upper_bound(s,s+len,b)-s;
printf("%d\n",id2-id1);
}
return 0;
}