Cod sursa(job #2360345)
Utilizator | Data | 1 martie 2019 18:42:43 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 50 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int fr[2000005];
int main()
{ int n,nrap=0;
f>>n;
fr[0]=fr[1]=1;
for(int i=2; i<=n; i++)
if(!fr[i])
{ nrap++;
for(int j=i+i; j<=n; j+=i) fr[j]=1;
}
g<<nrap;
return 0;
}