Cod sursa(job #850666)
Utilizator | Data | 8 ianuarie 2013 19:07:58 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int N,ciur[2000000],nrp;
int main()
{ fin>>N;
for(int i=2;i<N;i++)
ciur[i]=i;
for(int i=2;i<=N;i++)
for(int j=i+i;j<=N;j+=i)
ciur[j]=0;
for(int i=0;i<N;i++)
if(ciur[i]!=0)
nrp++;
fout<<nrp;
return 0;
}