Cod sursa(job #522047)

Utilizator raduiris94Alexa Radu raduiris94 Data 14 ianuarie 2011 10:19:10
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.3 kb
Raporteaza aceasta sursa 
#include <cstdio>
int n, c;
bool a[2000005];
int main() 
{
    int i, j;
	FILE *f=fopen("ciur.in", "r");
	FILE *g=fopen("ciur.out", "w");
	fscanf(f, "%d", &n);
    for(i=2; i<=n; ++i)
	if (!a[i]) 
	{
		++c;
		for (j = i+i; j<=n; j+=i)
			a[j]=1;
	}
    fprintf(g, "%d\n", c);
    return 0;
}