Cod sursa(job #1111432)
Utilizator | Data | 18 februarie 2014 21:17:12 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.36 kb |
#include<fstream>
#include<math.h>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int v[2000001];
int main()
{
int n,i,s=1,j;
f>>n;
for(i=3;i<=n;i+=2)
{
if(v[i]==0)
{
for(j=i+i+i;j<=n;j+=i+i)
v[j]=1;
s++;
}
}
g<<s;
return 0;
}