Cod sursa(job #1131968)
Utilizator | Emanuel Nrx StarGold2 | Data | 2 martie 2014 12:19:04 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include<fstream>
using namespace std;
ifstream fin("a.in");
ofstream fout("a.out");
char v[20000005];
int i,n,j,nr;
int main () {
fin>>n;
for(i=2;i<=n;i++){
if(v[i]==0){
nr++;
for(j=i+i;j<=n;j+=i)
v[j]=1;
}
}
fout<<nr;
return 0;
}