Cod sursa(job #217107)
Utilizator | Data | 27 octombrie 2008 00:08:57 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include "fstream.h"
#include "math.h"
int main()
{long n,s=0,i,j;
char prim[2000005];
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;i++)
prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i])
{s++;
for(j=i+i;j<=n;j+=i)
prim[j]=0;
}
g<<s;
return 0;
}