Cod sursa(job #1772068)
Utilizator | Data | 6 octombrie 2016 14:45:38 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.32 kb |
#include<iostream>
#include<fstream>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
bool A[2000001];
int n;
int r = 0;
int main()
{
fin >> n;
for (int i = 2; i <= n; i++)
{
if (A[i] == 0)
{
r++;
for (int j = i; j <= n;j+=i)
{
A[j] = 1;
}
}
}
fout << r;
}