Function depth_first_search

src/utils/graph.cpp:190–226

}

std::vector<El::Int>
depth_first_search(El::Int root,
                   const std::map<El::Int, std::set<El::Int>>& edges)
{

  // Initialize data structures
  std::unordered_map<El::Int, bool> is_visited, is_sorted;
  std::vector<El::Int> sorted_nodes;
  std::stack<El::Int> search_stack;
  search_stack.push(root);

  // Visit nodes until search stack is exhausted
  while (!search_stack.empty()) {
    const auto& node = search_stack.top();
    search_stack.pop();
    if (!is_sorted[node]) {
      if (is_visited[node]) {
        // Add node to sorted list if we have already visited
        is_sorted[node] = true;
        sorted_nodes.push_back(node);
      }
      else {
        // Visit node and add neighbors to search stack
        is_visited[node] = true;
        search_stack.push(node);
        for (const auto& neighbor : get_neighbors(node, edges)) {
          if (!is_visited[neighbor] && !is_sorted[neighbor]) {
            search_stack.push(neighbor);
          }
        }
      }
    }
  }

  // Return list of sorted nodes
  return sorted_nodes;
}

std::vector<El::Int>
topological_sort(const std::set<El::Int>& nodes,