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:13:28: error: extended character ’ is not valid in an identifier
   13 |         if (board[i][j] == ’#’) continue;
      |                            ^
a.cc:13:29: error: stray '#' in program
   13 |         if (board[i][j] == ’#’) continue;
      |                             ^
a.cc:13:30: error: extended character ’ is not valid in an identifier
   13 |         if (board[i][j] == ’#’) continue;
      |                              ^
a.cc:22:34: error: extended character ’ is not valid in an identifier
   22 |             if (board[ni][nj] == ’#’) num++;
      |                                  ^
a.cc:22:35: error: stray '#' in program
   22 |             if (board[ni][nj] == ’#’) num++;
      |                                   ^
a.cc:22:36: error: extended character ’ is not valid in an identifier
   22 |             if (board[ni][nj] == ’#’) num++;
      |                                    ^
a.cc:25:30: error: extended character ’ is not valid in an identifier
   25 |     board[i][j] = char(num + ’0’);
      |                              ^
a.cc:25:30: error: extended character ’ is not valid in an identifier
a.cc: In function 'int main()':
a.cc:3:1: error: 'cin' was not declared in this scope
    3 | cin >> h >> w;
      | ^~~
a.cc:5:1: error: 'string' was not declared in this scope
    5 | string board[50];
      | ^~~~~~
a.cc:7:36: error: 'board' was not declared in this scope
    7 | for (int i = 0; i < h; ++i) cin >> board[i];
      |                                    ^~~~~
a.cc:13:13: error: 'board' was not declared in this scope
   13 |         if (board[i][j] == ’#’) continue;
      |             ^~~~~
a.cc:13:28: error: '\U00002019' was not declared in this scope
   13 |         if (board[i][j] == ’#’) continue;
      |                            ^
a.cc:13:29: error: expected ')' before '\U00002019'
   13 |         if (board[i][j] == ’#’) continue;
      |            ~                ^~
      |                             )
a.cc:22:17: error: 'board' was not declared in this scope
   22 |             if (board[ni][nj] == ’#’) num++;
      |                 ^~~~~
a.cc:22:34: error: '\U00002019' was not declared in this scope
   22 |             if (board[ni][nj] == ’#’) num++;
      |                                  ^
a.cc:22:35: error: expected ')' before '\U00002019'
   22 |             if (board[ni][nj] == ’#’) num++;
      |                ~                  ^~
      |                                   )
a.cc:25:5: error: 'board' was not declared in this scope
   25 |     board[i][j] = char(num + ’0’);
      |     ^~~~~
a.cc:25:30: error: '\U000020190\U00002019' was not declared in this scope
   25 |     board[i][j] = char(num + ’0’);
      |                              ^~~
a.cc:30:29: error: 'cout' was not declared in this scope
   30 | for (int i = 0; i < h; ++i) cout << board[i] << endl;
      |                             ^~~~
a.cc:30:37: error: 'board' was not declared in this scope
   30 | for (int i = 0; i < h; ++i) cout << board[i] << endl;
      |                                     ^~~~~
a.cc:30:49: error: 'endl' was not declared in this scope
   30 | for (int i = 0; i < h; ++i) cout << board[i] << endl;
      |                                                 ^~~~