func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 1e9 + 7;   const int INF = 0x3f3f3f3f;   const int MAXN = 2005;   int n, m;   char maze[MAXN][MAXN];   void Dfs(int x, int y) {     if (x >= n - 1 || y >= m - 1 || x < 0 || y < 0) return;     int xx, yy, s = 0;     for (int i = 0; i < 2; ++i)       for (int j = 0; j < 2; ++j)         if (maze[x + i][y + j] ==  * ) {           s++;           xx = x + i;           yy = y + j;         }     if (s == 1) {       maze[xx][yy] =  . ;       for (int i = -1; i < 1; ++i)         for (int j = -1; j < 1; ++j) Dfs(xx + i, yy + j);     }   }   int main(int argc, char const *argv[]) {     scanf( %d %d , &n, &m);     for (int i = 0; i < n; ++i) scanf( %s , maze[i]);     for (int i = 0; i < n - 1; ++i)       for (int j = 0; j < m - 1; ++j) Dfs(i, j);     for (int i = 0; i < n; ++i) printf( %s n , maze[i]);     return 0;   }   