Cod sursa(job #400574)
Utilizator | Data | 21 februarie 2010 17:30:47 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include<fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
long x[2000001], i, j, n, nr;
int main(){
f>>n;
for(i=2;i<=n;i++)
if(x[i]==0){
nr++;
for(j=2*i;j<=n;j+=i)
x[j]=1;
}
g<<nr;
f.close();
g.close();
return 0;
}