Cod sursa(job #850679)
Utilizator | Data | 8 ianuarie 2013 19:25:19 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int N,ciur[2000005],nrp;
int main()
{ fin>>N;
for(int i=2;i<N;i++)
ciur[i]=1;
for(int i=2;i<=N;i++)
{ if(ciur[i]==1)
nrp++;
for(int j=2*i;j<=N;j+=i)
ciur[j]=0;
}
fout<<nrp;
return 0;
}