Cod sursa(job #798341)
Utilizator | Data | 16 octombrie 2012 13:41:43 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include<fstream>
using namespace std;
int main(){
ifstream f("ciur.in");
ofstream g("ciur.out");
long long n,j,i,nr;
f>>n;
bool v[2000001]={false};
nr=1;
for(i=3;i<=n;i=i+2){
if (v[i]==false){
nr++;
for (j=i*i;j<=n;j=j+i){
v[j]=true;
}
}
}
g<<nr;
return 0;
}