Cod sursa(job #2093464)
Utilizator | Data | 23 decembrie 2017 18:48:55 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include<fstream>
using namespace std;
char v[2000001];
int main()
{long long n,i,j,k=0;
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;i++)
if(!v[i])
{k++;
for(j=i*i;j<=n;j+=i)
v[j]=1;
}
g<<k;
f.close();
g.close();
return 0;}