Cod sursa(job #787172)
Utilizator | Data | 12 septembrie 2012 19:40:02 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<fstream>
#include<math.h>
using namespace std;
int n, nrp, x, j;
char v[2000001];
int main(){
ifstream cin("ciur.in");
ofstream cout("ciur.out");
cin>>n;
for(x=2; x<=n; x++){
if(v[x]==0){
nrp++;
for(j=x+x; j<=n; j+=x)
v[j]=1;
}
}
cout<<nrp;
return 0;
}