Cod sursa(job #498155)
Utilizator | Data | 4 noiembrie 2010 12:29:31 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.46 kb |
#include <iostream>
using namespace std;
const int DIM = 2000001;
bool c[DIM];
int n, nr;
int main()
{ FILE *f=fopen("ciur.in","r");
FILE *g=fopen("ciur.out", "w");
int i,j;
fscanf(f,"%d", &n);
for(i=2; i<=n; ++i)
if(!c[i])
for (j=2 * 1;j<=n; j +=i)
c[j] = 1;
for(i = 2; i<=n; ++i)
if(!c[i])
++nr;
fprintf(g , "%d" , nr);
return 0;
}