Cod sursa(job #662238)
Utilizator | Data | 16 ianuarie 2012 10:41:12 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
using namespace std;
#include<fstream>
int main()
{
ifstream f("ciur.in");
ofstream g("ciur.out");
char prim[2000001];
int n,i,j,contor=0;
f>>n;
for(i=1; i<=n; i++)
prim[i]=1;
for(i=2;i<=n;i++)
{ if(prim[i]==1)
{contor++;
for(j=i+i; j<=n; j=j+i)
prim[j]=0;
}
}
g<<contor;
return 0;
}