Cod sursa(job #1155389)
Utilizator | Data | 26 martie 2014 21:19:27 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include <fstream>
#include <bitset>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
bitset <2000001> v;
int main()
{
int sol=1,i,j,N;
fin>>N;
for(i=3;i<N;i+=2)
{
if(!v[i]) {sol++;for(j=i*i;j<N;j+=i) v[j]=1;}
}
fout<<sol;
}