Cod sursa(job #2448826)
Utilizator | Data | 17 august 2019 15:30:16 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.46 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f ("ciur.in");
ofstream g ("ciur.out");
vector<bool> v;
int ciur(int n)
{
int nr=0;
v.resize(n+1, 1);
v[0]=v[1]=0;
for(int i=2; i<=n; i++)
if(v[i])
{
nr++;
for(int j=2*i; j<=n; j+=i)
v[j]=0;
}
return nr;
}
int main()
{
int n;
f>>n;
g<<ciur(n);
f.close();
g.close();
return 0;
}