message: Update bricks-falling-when-hit.cpp
diff: @@ -35,14 +35,14 @@ public:
  vector<int> result;
  for (int i = hits.size() - 1; i >= 0; --i) {
  - int r = hits[i][0], c = hits[i][1];
  + const auto r = hits[i][0], c = hits[i][1];
  const auto prev_roof = union_find.top();
  if (grid[r][c] == 0) {
  result.emplace_back(0);
  continue;
  }
  for (const auto& d : directions) {
  - int nr = r + d.first, nc = c + d.second;
  + const auto nr = r + d.first, nc = c + d.second;
  if (0 <= nr && nr < R &&
  0 <= nc && nc < C &&
  hit_grid[nr][nc]) {
  