Cod sursa(job #2036699)
Utilizator | Data | 10 octombrie 2017 23:01:53 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.35 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
bool prim[100000001];
int main()
{long long n;int nr=0;
fin>>n;
for(int i=2;i<=n;i++)
{
if(!prim[i])
for(int j=i+i;j<=n;j+=i)
prim[j]=1;
if(prim[i]==0)++nr;
}
fout<<nr;
}