Cod sursa(job #3038128)
Utilizator | Data | 26 martie 2023 21:22:06 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.45 kb |
#include <fstream>
using namespace std;
ifstream cin("ciur.in");
ofstream cout("ciur.out");
int n,i,j,nr;
bool ciur[2000004];
int main()
{
cin>>n;
ciur[1]=1;
ciur[0]=1;
for(i=2; i<=2000000; i++)
if(ciur[i]==0)
{
if(i<=n)
nr++;
else
break;
for(j=i;j*i<=2000000;j++)
ciur[i*j]=1;
}
cout<<nr;
return 0;
}