全是WA，救我！

#include <iostream>
using namespace std;

int main()
{
	bool l[5005], flag; int n;
	for (int i = 1; i <= 5005; i++) l[i] = true;
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		if (i % 2 == 0) flag = true;
		else flag = false;
		for (int j = i; j <= n; j += i)
			l[j] = false;
	}
	for (int i = 1; i <= n; i++)
		if (l[i]) cout << l[i] << ' ';
	return 0;
}