Cod sursa(job #264229)
Utilizator | Data | 21 februarie 2009 20:01:58 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include<fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
int n;
char p[2000005];
int main(){
int i,j,nr;
nr=0;
f>>n;
for(i=2;i<=n;i++)
if(p[i]==0){
nr++;
for(j=2;i*j<=n;j++)
p[i*j]=1;
}
g<<nr;
return 0;
}