Cod sursa(job #2253741)
Utilizator | Data | 4 octombrie 2018 12:36:34 | |
---|---|---|---|
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,i,j,sol;
short f[2000020];
int main () {
fin>>n;
for (i=2;i<=n;i++) {
if (f[i]==0) {
sol++;
for (j=i*i;j<=n;j+=i)
f[j]=1;
}
}
fout<<sol;
}