Cod sursa(job #414304)
Utilizator | Data | 9 martie 2010 22:06:08 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.27 kb |
#include<fstream.h>
int n,i,j,v[2000001],nr ;
int main()
{
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=1;i<=n;i++)
v[i]=i;
for(i=2;i<=n;i++)
for(j=i+i;j<=n;j+=i)
v[j]=0;
nr=0;
for(i=2;i<=n;i++)
if(v[i]) nr++;
g<<nr;
}