0pts求调

#include <iostream>
#include <algorithm>
#define Please return
#define AC 0
//#pragma GCC optimize(2)
//#pragma GCC optimize(3)
using namespace std;
const int MAXN = 30 + 5;
int n, g[MAXN][MAXN];
bool vis[MAXN][MAXN];

int dx[] = {0, +1, 0, -1, 0, 0};
int dy[] = {0, 0, -1, 0, +1, 0};

void dfs(int x, int y) {
	vis[x][y] = true;
	for (int i = 1; i <= 4; i++) {
		int nx = x + dx[i];
		int ny = y + dy[i];
		if (nx < 1 || nx > n || ny < 1 || ny > n) {
			continue;
		}
		if (g[nx][ny] == '0') {
			continue;
		}
		if (vis[nx][ny]) {
			continue;
		}
		g[nx][ny] = 3;
		dfs(nx, ny);
	}
}

int main() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			cin >> g[i][j];
		}
	}
	dfs(1, 1);
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) {
			if (g[i][j] == 3) {
				cout << 1 << " ";
			} else if (g[i][j] == 1) {
				cout << 2 << " ";
			} else {
				cout << 0 << " ";
			}
		}
		cout << endl;
	}
	Please AC;
}