Cod sursa(job #2303746)
Utilizator | Data | 16 decembrie 2018 20:40:07 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
char prim[200000000];
int main(){
int n,contor=0;
fin>>n;
for(int i=2;i<=n;i++)
prim[i]=1;
for(int i=2;i<=n;i++)
if(prim[i]){
contor++;
for(int j=i+i;j<=n;j+=i)
prim[j]=0;
}
fout<<contor;
return 0;
}