Cod sursa(job #638139)
Utilizator | Data | 20 noiembrie 2011 19:07:20 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include <cstdlib>
#include <iostream>
#include<fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
bool prim[2000002];
int main(){
int n,nr=0;
f>>n;
for(int i=2;i<=n;i++)
if(prim[i]==0){
nr++;
for(int j=i;j<=n;j=j+i)
prim[j]=1;
}
g<<nr;
return 0;
}