Cod sursa(job #1916909)
Utilizator | Data | 9 martie 2017 10:39:00 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include <fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int a[2000005],i,j,n,nrPrime;
int main()
{
fin>>n;
for(i=2;i<=n;i++)
{
if(a[i]==0)
{
nrPrime++;
for(j=i*i;j<=n;j+=i)a[j]=1;
}
}
fout<<nrPrime;
return 0;
}