Cod sursa(job #743686)
Utilizator | Data | 5 mai 2012 14:47:59 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include<fstream.h>
long int a[1000000],i,j,x,np;
int main()
{
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>x;
for(i=2;i<=x;i++)
a[i]=1;
for(i=2;i<=x;i++)
if(a[i]==1)
for(j=i+i;j<=x;j=j+i)
a[j]=0;
for(i=2;i<=x;i++)
if(a[i]==1) np++;
g<<np;
return 0;
}