백준 감시 C++

#include <iostream>
#include <vector>
#include <cstring>
#include <algorithm>

using namespace std;
const int MAX = 9;
int n, m;
int map[MAX][MAX];
int copys[MAX][MAX];
vector<pair<int, int>> camera;
int visited[MAX][MAX][4];
int answer = 987654321;
vector<int> angle;
struct Move {
	int x, y;
};
Move mv[4] = { {0,1}, {-1,0}, {0,-1}, {1,0} };

void copymap() {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			map[i][j] = copys[i][j];
		}
	}
}

void calanswer() {
	int value = 0;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if (map[i][j] == 0) 
				value++;
		}
	}
	answer = min(answer, value);
}

void dfs(int count) {
	if (count == camera.size()) {
		for (int i = 0; i < camera.size(); i++) {
			int currenti = camera[i].first;
			int currentj = camera[i].second;

			for (int k = 0; k < 4; k++) {
				if (visited[currenti][currentj][k] == 1) {
					int movei = currenti + mv[(angle[i] + k)%4].x;
					int movej = currentj + mv[(angle[i] + k)%4].y;

					while (true) {
						if (map[movei][movej] == 6)
							break;
						if (!(movei >= 0 && movei < n && movej >= 0 && movej < m))
							break;
						if(map[movei][movej] == 0)
							map[movei][movej] = -1;
						movei = movei + mv[(angle[i] + k)%4].x;
						movej = movej + mv[(angle[i] + k)%4].y;
					}
				}
			}
		}
		calanswer();
		copymap();
		return;
	}
	for (int i = 0; i < 4; i++) {
		angle.push_back(i);
		dfs(count + 1);
		angle.pop_back();
	}
	return;
}

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

	memset(visited, -1, sizeof(visited));
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cin >> map[i][j];
			copys[i][j] = map[i][j];
			if (map[i][j] == 1) {
				visited[i][j][0] = 1;
				camera.push_back(make_pair(i, j));
			}
			else if (map[i][j] == 2) {
				visited[i][j][0] = 1;
				visited[i][j][2] = 1;
				camera.push_back(make_pair(i, j));
			}
			else if (map[i][j] == 3) {
				visited[i][j][0] = 1;
				visited[i][j][1] = 1;
				camera.push_back(make_pair(i, j));
			}
			else if (map[i][j] == 4) {
				visited[i][j][0] = 1;
				visited[i][j][1] = 1;
				visited[i][j][2] = 1;
				camera.push_back(make_pair(i, j));
			}
			else if (map[i][j] == 5) {
				visited[i][j][0] = 1;
				visited[i][j][1] = 1;
				visited[i][j][2] = 1;
				visited[i][j][3] = 1;
				camera.push_back(make_pair(i, j));
			}
		}
	}
	dfs(0);
	cout << answer << endl;
	return 0;
}