输入:

6
0 0 0 0 0 0
0 0 1 1 1 1
0 1 1 0 0 1
1 1 0 0 0 1
1 0 0 0 0 1
1 1 1 1 1 1

输出:

0 0 0 0 0 0
0 0 1 1 1 1
0 1 1 2 2 1
1 1 2 2 2 1
1 2 2 2 2 1
1 1 1 1 1 1

代码如下:

#include <iostream>
using namespace std;
const int N  = 40;
int mp[N][N], mps[N][N];int n;int dx[] = {0, 0, 1, -1}, dy[] = {1, -1, 0, 0};void dfs(int x, int y) {for (int i  = 0; i < 4; i++) {int xx = x + dx[i], yy = y + dy[i];if (xx < 0 || xx > n + 1 || yy < 0 || yy > n + 1 || mps[xx][yy])continue;mps[xx][yy] = 1;dfs(xx, yy);}
}int main() {cin >> n;for (int i = 1; i <= n; i++)for (int j  = 1; j <= n; j++) {cin >> mp[i][j];mps[i][j] = mp[i][j];}dfs(0, 0);for (int i  = 1; i <= n; i++) {for (int j = 1; j <= n; j++) {if (mps[i][j])cout << mp[i][j] << " ";elsecout << 2 << " ";}cout << endl;}return 0;}