Cod sursa(job #696472)
Utilizator | Data | 28 februarie 2012 18:41:06 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.22 kb |
#include<fstream>
using namespace std;
char c[2000001];
int main()
{int n,i,j,s=0;
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;++i)
if(!c[i])
{s++;
for(j=2*i;j<=n;j+=i)
c[j]=1;}
g<<s;
}