Cod sursa(job #852033)
Utilizator | Data | 10 ianuarie 2013 19:29:11 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 60 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int N,nrp;
char ciur[2000000];
int main()
{ fin>>N;
for(int i=2;i<=N;i++)
{ if(ciur[i]==0)
nrp++;
for(int j=i+i;j<=N;j+=i)
ciur[j]=1;
}
fout<<nrp;
return 0;
}