백준 16234번 C++

#include <iostream>
#include <cstring>
#include <queue>
#include <vector>

using namespace std;
const int MAX = 51;
int n, l, r;
int map[MAX][MAX];
bool possible = false;
int visited[MAX][MAX];

struct Move {
	int x, y;
};
Move mv[4] = { {1,0}, {0,1}, {-1,0}, {0,-1} };

void bfs(int i, int j) {
	int sum = 0;
	queue<pair<int, int>> q;
	vector<pair<int, int>> temp;
	q.push(make_pair(i, j));
	temp.push_back(make_pair(i, j));
	sum += map[i][j];
	visited[i][j] = 1;

	while (!q.empty()) {
		int currenti = q.front().first;
		int currentj = q.front().second;
		q.pop();

		for (int k = 0; k < 4; k++) {
			int movei = currenti + mv[k].x;
			int movej = currentj + mv[k].y;

			if (movei >= 0 && movei < n && movej >=0 && movej < n) {
				int minus = abs(map[currenti][currentj] - map[movei][movej]);
				if (visited[movei][movej] == -1 && minus >= l && minus <= r) {
					q.push(make_pair(movei, movej));
					temp.push_back(make_pair(movei, movej));
					visited[movei][movej] = 1;
					sum += map[movei][movej];
				}
			}
		}
	}
	if (temp.size() > 1)
		possible = true;
	int value = sum / temp.size();
	for (int k = 0; k < temp.size(); k++) {
		map[temp[k].first][temp[k].second] = value;
	}
	return;
}

int main(void) {
	int answer = 0;
	cin >> n >> l >> r;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cin >> map[i][j];
		}
	}

	do {
		possible = false;
		memset(visited, -1, sizeof(visited));

		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				if (visited[i][j] == -1) 
					bfs(i, j);
			}
		}
		answer++;
	} while (possible);
	cout << answer-1 << endl;
	return 0;
}