点击查看测评结果 上代码：

# include<bits/stdc++.h>
using namespace std;
int ar[33][33];
int n;
struct point {
	int x, y;

};
const int xj[4] = {-1, 1, 0, 0};
const int yj[4] = {0, 0, -1, 1};

int bfs(int x, int y) {
	point S;
	S.x=x;
	S.y=y;
	if (ar[x][y] != 0)return 0;
	point pts[24111];
	int ptsi = 0;
	pts[ptsi] = S;
	ptsi++;
	ar[S.x][S.y] = -1;
	int flag = 1, cnt = 0;
	while (flag) {
		flag = 0;
		vector<point> newp;

		for (int i = 0; i < ptsi; i++) {



			for (int j = 0; j < 4; j++) {
				point wz = pts[i];
				wz.x += xj[j];
				wz.y += yj[j];
				if (wz.x >= 0 && wz.x < x && wz.y >= 0 && wz.y < y && ar[wz.x][wz.y] == 0) {
					flag = 1;
					newp.push_back(wz);
					ar[wz.x][wz.y] = -1;
				}
			}

		}
		ptsi = 0;
		for (int i = 0; i < newp.size(); i++) {
			pts[ptsi] = newp[i];
			ptsi++;
		}

	}
	return 0;
}
int main() {
	cin >> n;
	char st[1001][1001];
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cin >> st[i][j];
		}
	}
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			ar[j][i] = st[i][j] - '0';

		}
	}
//	cout << " ";
//	for (int i = 0; i < n; i++) {
//		cout << "__";
//	}
//	cout << endl;
//	for (int i = 0; i < n; i++) {
//		cout << "|";
//		for (int j = 0; j < n; j++) {
//
//			cout << (ar[j][i] ? "█ " : "  ");
//		}
//		cout << "|\n";
//	}
//	cout << " ";
//	for (int i = 0; i < n; i++) {
//		cout << "￣";
//	}
	for (int i = 0; i < n; i++) {
		bfs(0, i);
	}
	for (int i = 1; i < n - 1; i++) {
		bfs(i, n - 1);
	}
	for (int i = n - 1; i >= 0; i--) {
		bfs(n - 1, i);
	}
	for (int i = n - 2; i > 0; i--) {
		bfs(i, 0);
	}
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (ar[j][i] == -1)cout << 0;
			else if (ar[j][i] == 0)cout << 2;
			else  if (ar[j][i] == 1)cout << 1;
		}
		cout << endl;
	}
	return 0;
}

注：用的是广搜。 能帮帮忙吗？