Cod sursa(job #1491915)
Utilizator | Data | 26 septembrie 2015 14:50:04 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.37 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream in ("ciur.in");
ofstream out ("ciur.out");
char p[2000001];
int main()
{
int n,nr=0,i,j;
in>>n;
for (i=2;i<=n;i++) p[i]=1;
for (i=2;i<=n;i++)
if (p[i]!=0)
{
nr++;
for (j=2*i;j<=n;j+=i) p[j]=0;
}
out<<nr;
return 0;
}