Cod sursa(job #445363)
Utilizator | Data | 23 aprilie 2010 17:11:14 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include<iostream>
#include<fstream.h>
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int main()
{
int i,j;
long n;
int nr=0;
char prim[2000005];
for(i=2;i<=n;i++)
prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i]==1)
{
nr++;
for(j=i+i;j<=n;j+=i)
prim[j]=0;
}
fout<<nr;
return 0;
}