Cod sursa(job #2000566)
Utilizator | Data | 14 iulie 2017 09:49:46 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 60 |
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 v[2000000];
int main()
{
int n, i, m, r=0;
fin >> n;
for(i = 2; i<n; i++)for(m = i + i; m<n; m+=i)v[m] = 1;
for(i = 2; i<n; i++)if(v[i]==0)r++;
fout << r;
return 0;
}