#include using namespace std; const int N = 40; int n; int a[N][N]; int b[N][N]; int dx[] = {0, 0, -1, 1}; int dy[] = {-1, 1, 0, 0}; struct coord { int x, y; }; //广度优先搜索 void bfs(int x, int y) { queue q; q.push({x, y}); while (!q.empty()) { coord p = q.front(); q.pop(); b[p.x][p.y] = -1; for (int i = 0; i < 4; i++) { int x1 = p.x + dx[i], y1 = p.y + dy[i]; if (b[x1][y1] >= 0 && x1 >= 1 && x1 <= n && y1 >= 1 && y1 <= n && a[x1][y1] == 0) { q.push({x1, y1}); b[x1][y1] = -1; } } } } int main() { //读入地图 cin >> n; for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) { cin >> a[i][j]; b[i][j] = a[i][j]; } //思路:从边缘(四条外边),找0,然后BFS找出所有区域,这些区域就是不被圈起来的范围,进行标识,再取反 for (int i = 1; i <= n; i++) if (a[1][i] == 0) bfs(1, i); //第一行 for (int i = 1; i <= n; i++) if (a[i][1] == 0) bfs(i, 1); //第一列 for (int i = 1; i <= n; i++) if (a[n][i] == 0) bfs(n, i); //最后一行 for (int i = 1; i <= n; i++) if (a[i][n] == 0) bfs(i, n); //最后一列 //输出 for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { if (b[i][j] == -1) cout << 0 << " "; else if (b[i][j] == 0) cout << 2 << " "; else cout << b[i][j] << " "; } cout << endl; } return 0; }