Cod sursa(job #955734)
Utilizator | Data | 1 iunie 2013 13:52:20 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include<fstream>
#define NMAX 2000000
#include<stdio.h>
#include<math.h>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int n,v[NMAX],i,j,k;
int main()
{
f>>n;
for(i=2;i<=n;i++)
v[i]=1;
for(i=2;i<=n;i++)
if(v[i]){k++;
for(j=2*i;j<=n;j=j+i)
v[j]=0; }
g<<k;
return 0;
}