Language: C++

int main(void) {
 int h, w;
 cin >> h >> w;

 string board[50];

 for (int i = 0; i < h; ++i) cin >> board[i];

 const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
 const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};

 for (int i = 0; i < h; ++i) {
 for (int j = 0; j < w; ++j) {
 if (board[i][j] == ’#’) continue;

 int num = 0;
 for (int d = 0; d < 8; ++ d) {
 const int ni = i + dy[d];
 const int nj = j + dx[d];

 if (ni < 0 or h <= ni) continue;
 if (nj < 0 or w <= nj) continue;
 if (board[ni][nj] == ’#’) num++;
 }

 board[i][j] = char(num + ’0’);

 }
 }

 for (int i = 0; i < h; ++i) cout << board[i] << endl;

 return 0;
 }

Compiler output:
a.cc:14:21: error: extended character ’ is not valid in an identifier
   14 |  if (board[i][j] == ’#’) continue;
      |                     ^
a.cc:14:22: error: stray '#' in program
   14 |  if (board[i][j] == ’#’) continue;
      |                      ^
a.cc:14:23: error: extended character ’ is not valid in an identifier
   14 |  if (board[i][j] == ’#’) continue;
      |                       ^
a.cc:23:23: error: extended character ’ is not valid in an identifier
   23 |  if (board[ni][nj] == ’#’) num++;
      |                       ^
a.cc:23:24: error: stray '#' in program
   23 |  if (board[ni][nj] == ’#’) num++;
      |                        ^
a.cc:23:25: error: extended character ’ is not valid in an identifier
   23 |  if (board[ni][nj] == ’#’) num++;
      |                         ^
a.cc:26:27: error: extended character ’ is not valid in an identifier
   26 |  board[i][j] = char(num + ’0’);
      |                           ^
a.cc:26:27: error: extended character ’ is not valid in an identifier
a.cc: In function 'int main()':
a.cc:3:2: error: 'cin' was not declared in this scope
    3 |  cin >> h >> w;
      |  ^~~
a.cc:5:2: error: 'string' was not declared in this scope
    5 |  string board[50];
      |  ^~~~~~
a.cc:7:37: error: 'board' was not declared in this scope
    7 |  for (int i = 0; i < h; ++i) cin >> board[i];
      |                                     ^~~~~
a.cc:14:6: error: 'board' was not declared in this scope
   14 |  if (board[i][j] == ’#’) continue;
      |      ^~~~~
a.cc:14:21: error: '\U00002019' was not declared in this scope
   14 |  if (board[i][j] == ’#’) continue;
      |                     ^
a.cc:14:22: error: expected ')' before '\U00002019'
   14 |  if (board[i][j] == ’#’) continue;
      |     ~                ^~
      |                      )
a.cc:23:6: error: 'board' was not declared in this scope
   23 |  if (board[ni][nj] == ’#’) num++;
      |      ^~~~~
a.cc:23:23: error: '\U00002019' was not declared in this scope
   23 |  if (board[ni][nj] == ’#’) num++;
      |                       ^
a.cc:23:24: error: expected ')' before '\U00002019'
   23 |  if (board[ni][nj] == ’#’) num++;
      |     ~                  ^~
      |                        )
a.cc:26:2: error: 'board' was not declared in this scope
   26 |  board[i][j] = char(num + ’0’);
      |  ^~~~~
a.cc:26:27: error: '\U000020190\U00002019' was not declared in this scope
   26 |  board[i][j] = char(num + ’0’);
      |                           ^~~
a.cc:31:30: error: 'cout' was not declared in this scope
   31 |  for (int i = 0; i < h; ++i) cout << board[i] << endl;
      |                              ^~~~
a.cc:31:38: error: 'board' was not declared in this scope
   31 |  for (int i = 0; i < h; ++i) cout << board[i] << endl;
      |                                      ^~~~~
a.cc:31:50: error: 'endl' was not declared in this scope
   31 |  for (int i = 0; i < h; ++i) cout << board[i] << endl;
      |                                                  ^~~~