백준 11559번 C++

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

using namespace std;
const int MAX = 12;
string map[MAX];
int visited[MAX][6];
struct Move {
	int x, y;
};
Move mv[4] = { {1,0},{-1,0}, {0,1}, {0,-1} };

bool cmp(pair<int, int> a, pair<int, int> b){

	if (a.first < b.first)
		return true;

	else if (a.first == b.first){
		if (a.second < b.second)
			return true;
		return false;
	}
	return false;
}

int bfs() {
	int answer = 0;

	while (1) {
		vector<pair<int, int>> puyopop;
		memset(visited, -1, sizeof(visited));
		for (int i = 0; i < MAX; i++) {
			for (int j = 0; j < 6; j++) {
				if (map[i][j] == '.' || visited[i][j] == 1)
					continue;
				queue<pair<int, int>> q;
				vector<pair<int, int>> cache;
				q.push(make_pair(i, j));
				visited[i][j] = 1;

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

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

						if (movei >= 0 && movei < 12 && movej >= 0 && movej < 6 && visited[movei][movej] == -1 && map[movei][movej] == map[currenti][currentj]) {
							visited[movei][movej] = 1;
							q.push(make_pair(movei, movej));
						}
					}
				}
				if (cache.size() >= 4) {
					for (int k = 0; k < cache.size(); k++) 
						puyopop.push_back(make_pair(cache[k].first, cache[k].second));
				}
			}
		}
		if (puyopop.size() > 0) {
			sort(puyopop.begin(), puyopop.end(), cmp);
			answer++;
			for (int k = 0; k < puyopop.size(); k++) {
				for (int i = puyopop[k].first; i >= 1; i--) {
					map[i][puyopop[k].second] = map[i - 1][puyopop[k].second];
				}
				map[0][puyopop[k].second] = '.';
			}
		}
		else
			break;
	}
	return answer;
}

int main(void) {
	
	for (int i = 0; i < MAX; i++) {
		cin >> map[i];
	}
	cout << bfs() << endl;
	return 0;
}