Cod sursa(job #679516)
Utilizator | Data | 13 februarie 2012 13:25:34 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include<fstream>
using namespace std;
long long i,j,n,nrprime;
bool prim[2000002];
int main()
{
ifstream f("ciur.in"); ofstream g("ciur.out"); f>>n;
for(i=2;i<=n;i++) prim[i]=1;
for(i=2;i<=n;i++)
if(prim[i]==1)
{nrprime++;
for(j=i+i;j<=n;j=j+i) prim[j]=0;}
g<<nrprime; return 0;
}