Cod sursa(job #1039422)
Utilizator | Data | 22 noiembrie 2013 23:32:55 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include <fstream>
using namespace std;
int n, c, s;
char a[2000005];
int main() {
int i, j;
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2; i<=n; i++)
if (!a[i]) { s++;
for (j = i+i; j<=n; j+=i)
a[j]=1;
}
g<<s;
return 0;
}