Cod sursa(job #533761)
| Utilizator |  Cornigeanu Calin Sadmann |
Data | 14 februarie 2011 16:43:05 |
|---|---|---|---|
| Problema | Ciurul lui Eratosthenes | Scor | 0 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.29 kb |
#include<stdio.h>
FILE *in=fopen("ciur.in","rt");
FILE *out=fopen("ciur.out","wt");
bool prim[2000000001];
int main()
{
fscanf(in,"%d",&n);
cont=1;
for(i=3;i<=n;i+=2)
{
if(!prim[i])
{
for(j=i<<1;j<=n;j+=i)
prim[j]=true;
cont++;
}
}
fprintf(out,"%d",cont);
}