BZOJ2393: Cirno的完美算数教室

时间:2021-08-16 23:24:32

2393: Cirno的完美算数教室

Time Limit: 10 Sec  Memory Limit: 128 MB
Submit: 138  Solved: 83
[Submit][Status]

Description

~Cirno发现了一种baka数,这种数呢~只含有2和⑨两种数字~~
现在Cirno想知道~一个区间中~~有多少个数能被baka数整除~
但是Cirno这么天才的妖精才不屑去数啦
只能依靠聪明的你咯。
 
 

Input

一行正整数L R
( 1 < L < R < 10^10)
 

Output

一个正整数,代表所求的答案
 

Sample Input

1 100

Sample Output

58

HINT

题解:

同幸运数字,第一次排rank1,哈哈!

代码:

 #include<cstdio>

 #include<cstdlib>

 #include<cmath>

 #include<cstring>

 #include<algorithm>

 #include<iostream>

 #include<vector>

 #include<map>

 #include<set>

 #include<queue>

 #include<string>

 #define inf 1000000000

 #define maxn 1200

 #define maxm 500+100

 #define eps 1e-10

 #define ll unsigned long long

 #define pa pair<int,int>

 #define for0(i,n) for(int i=0;i<=(n);i++)

 #define for1(i,n) for(int i=1;i<=(n);i++)

 #define for2(i,x,y) for(int i=(x);i<=(y);i++)

 #define for3(i,x,y) for(int i=(x);i>=(y);i--)

 #define mod 1000000007

 using namespace std;

 inline ll read()

 {

     ll x=,f=;char ch=getchar();

     while(ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}

     while(ch>=''&&ch<=''){x=*x+ch-'';ch=getchar();}

     return x*f;

 }
ll l,r,ans,tot,n,a[maxn],b[maxn];
ll v[maxn];
inline void dfs(ll x)
{
if(x>r)return;
if(x)a[++tot]=x;
dfs(*x+);
dfs(*x+);
}
inline ll gcd(ll x,ll y)
{
return y?gcd(y,x%y):x;
}
inline void calc(ll x,int y,int z)
{
if(y>n)
{
if(z&)ans+=r/x-(l-)/x;
else if(z)ans-=r/x-(l-)/x;
return;
}
calc(x,y+,z);
ll t=(x/gcd(x,a[y]))*a[y];
if(t<=r)calc(t,y+,z+);
} int main() { freopen("input.txt","r",stdin); freopen("output.txt","w",stdout); l=read();r=read();
dfs();
sort(a+,a+tot+);
for1(i,tot)
if(!v[i])
{
b[++n]=a[i];
for2(j,i+,tot)if(a[j]%a[i]==)v[j]=;
}
for1(i,n)a[n+-i]=b[i];
calc(,,);
printf("%lld\n",ans); return ; }