Cod sursa(job #1480356)
Utilizator | Data | 2 septembrie 2015 15:06:31 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include <fstream>
#define N 2000010
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,i,j,cnt;
char viz[N];
int main()
{
f>>n;
for(i=2;i<=n;i++)
if(!viz[i])
{
cnt++;
for(j=i;j<=n;j+=i)
viz[j]=1;
}
g<<cnt<<"\n";
return 0;
}