Cod sursa(job #837699)
Utilizator | Data | 18 decembrie 2012 15:10:23 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.26 kb |
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,j,i,nr;
char a[2000001];
int main(){
f>>n;
nr=0;
for(i=2;i<=n;i++)
if(a[i]==0){
nr++;
for(j=2*i;j<=n;j=j+i)
a[j]=1;
}
g<<nr;
return 0;
}