Cod sursa(job #2025432)
Utilizator | Data | 22 septembrie 2017 18:22:23 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.29 kb |
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int n,i,v[2000001],c,j;
int main(){
fin>>n;
c=0;
for(i=3;i<=n;i=i+2){
if(v[i]==0){
c++;
for(j=i+i;j<=n;j+=i)
v[j]=1;
}
}
fout<<c;
return 0;
}