Cod sursa(job #1075856)
Utilizator | Data | 9 ianuarie 2014 17:39:57 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include <fstream>
#include <cmath>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int i,n,t,j;
char v[2000005];
int main()
{f>>n;
for(i=2;i<=n;i++)
v[i]=0;
for(i=2;i<=n;i++){
if(v[i]==0){
t++;
for(j=2*i;j<=n;j+=i)
v[j]=1;}
}
g<<t;
return 0;
}