백준 2468번 - C++

#include <bits/stdc++.h>
using namespace std;
#define X first
#define Y second
int board[102][102];
int vis[102][102];
int n;
int dx[4] = { 1,0,-1,0 };
int dy[4] = { 0,1,0,-1 };

int main(void) {
	ios::sync_with_stdio(0);
	cin.tie(0);

	cin >> n;
	int val = 0, ans = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cin >> board[i][j];
			val = max(board[i][j], val);
		}
	}
	while (val--) {
		int area = 0;
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				if (board[i][j] <= val) vis[i][j] = 1;
				else vis[i][j] = 0;
			}
		}

		queue<pair<int, int> > Q;
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				if (vis[i][j] == 1) continue;
				Q.push({ i,j });
				vis[i][j] = 1;
				area++;
				while (!Q.empty()) {
					pair<int, int> cur = Q.front(); Q.pop();
					//cout << '(' << cur.X << ", " << cur.Y << ") -> ";
					for (int dir = 0; dir < 4; dir++) {
						int nx = cur.X + dx[dir];
						int ny = cur.Y + dy[dir];
						if (nx < 0 || nx >= n || ny < 0 || ny >= n) continue;
						if (vis[nx][ny]) continue;
						vis[nx][ny] = 1;
						Q.push({ nx,ny });
					}
				}
			}
		}
		ans = max(ans, area);
	}
	cout << ans;
}