Fraktaali

input/code.cpp: In function 'std::vector<std::basic_string<char> > reverse(std::vector<std::basic_string<char> >)':
input/code.cpp:9:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < sq.size(); i++) {
                              ^
input/code.cpp:11:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 0; j < sq[i].length(); j++) {
                                    ^
input/code.cpp: In function 'std::vector<std::basic_string<char> > frak(int)':
input/code.cpp:26:31: error: 'pow' was not declared in this scope
  vector<string> a(pow(2, n - 1));
                               ^
input/code.cpp:29:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < nn.size(); i++) {
                              ^
input/code.cpp:33:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i...

#include <iostream>
#include <string>
#include <vector>

using namespace std;

vector<string> reverse(vector<string> sq) {
	vector<string> v;
	for (int i = 0; i < sq.size(); i++) {
		string s;
		for (int j = 0; j < sq[i].length(); j++) {
			s += sq[i][j] == '#' ? '.' : '#';
		}
		v.push_back(s);
	}
	return v;
}

vector<string> frak(int n) {
	if (n == 1)
		return vector<string> {{"#"}};

	vector<string> nn = frak(n - 1);
	vector<string> rn = reverse(nn);

	vector<string> a(pow(2, n - 1));

	// ylä
	for (int i = 0; i < nn.size(); i++) {
		a[i] = nn[i] + nn[i];
	}
	//ala
	for (int i = nn.size(); i < nn.size()*2; i++) {
		a[i] = nn[i - nn.size()] + rn[i - nn.size()];
	}

	return a;
}

void printV(vector<string> v) {
	for (int i = 0; i < v.size(); i++) {
		cout << v[i] << endl;
	};
	cout << "" << endl;
}

int main() {
	int n;
	cin >> n;

	printV(frak(n));
	return 0;
}