message: Update count-sub-islands.cpp
diff: @@ -28,8 +28,8 @@ private:
  }
  (*grid2)[i][j] = 0;
  int result = grid1[i][j];
  - for (const auto& [ni, nj] : directions) {
  - result &= dfs(grid1, grid2, i + ni, j + nj);
  + for (const auto& [di, dj] : directions) {
  + result &= dfs(grid1, grid2, i + di, j + dj);
  }
  return result;
  }
  