Cod sursa(job #1968678)
Utilizator | Data | 17 aprilie 2017 19:59:19 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
bool ciur[2000001];
int k,n;
int main()
{
f>>n;
for(int i=2;i<=n;i++)
if(ciur[i]==0)
{
k++;
for(int d=i*2;d<=n;d+=i)ciur[d]=1;
}
g<<k;
return 0;
}