Sieve_of_Eratosthenes.cpp

#include <bits/stdc++.h>
using namespace std;

void SieveOfEratosthenes(int n)
{

	bool prime[n + 1];
	memset(prime, true, sizeof(prime));

	for (int p = 2; p * p <= n; p++)
	{

		if (prime[p] == true)
		{

			for (int i = p * p; i <= n; i += p)
				prime[i] = false;
		}
	}


	for (int p = 2; p <= n; p++)
		if (prime[p])
			cout << p << " ";
}


int main()
{
	int n ;
  cin>>n;
	cout << " Prime numbers lesser than or equal to "
          << n << endl;
	SieveOfEratosthenes(n);
	return 0;
}