Cod sursa(job #1877747)
Utilizator | Data | 13 februarie 2017 18:19:25 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.43 kb |
#include<bits/stdc++.h>
using namespace std;
int x,a[2000000],b[2000000],k;
bool f[2000000];
int main(){
//ifstream cin("ciur.in");
//ofstream cout("ciur.out");
cin>>x;
for(int i=2;i<=x;i++){
if(i%2==0) f[i]=1;
if(i%3==0) f[i]=1;
if(i%5==0) f[i]=1;
}
for(int i=2;i<=x;i++){
if(f[i]==0) k++;
}
if(x<=2) cout<<1;
else if(x==3) cout<<2;
else if(x<=5&&x>3) cout<<3;
else cout<<k+3;
return 0;
}