Cod sursa(job #690357)
Utilizator | Data | 25 februarie 2012 16:00:38 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
char p[2000001];
void ciur(int n,int &k)
{
int i,j;k=0;
for (i=2;i<=n;i++)
p[i]=1;
for (i=2;i<=n;i++)
if (p[i]==1)
{
k++;
for (j=i+i;j<=n;j+=i)
p[j]=0;
}
}
int main()
{
int n,k=0;
f>>n;
ciur(n,k);
g<<k;
return 0;
}