tree

#include <gempba/utils/tree.hpp>  // included automatically via gempba.hpp

tree is an index-based tree data structure. Nodes are stored in a flat std::vector and identified by integer index. Each node tracks its parent, left and right siblings, and an ordered child list, all via raw pointers into the same vector.

Used internally by the semi-centralized scheduler to represent the process assignment topology built during the startup phase. Not intended for direct use in user code.

Non-copyable. Movable.

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Constructors

explicit tree(std::size_t size);

Pre-allocate size nodes, indexed 0 … size-1.

tree();

Construct an empty tree. Call resize() before accessing nodes.

void resize(std::size_t size);

Append size additional nodes to the existing tree.

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Tree access

tree_node& operator[](int index);

Returns a reference to the node at index.

std::size_t size() const;

Returns the total number of nodes in the tree.

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tree_node

Each node exposes the following interface.

Mutation

void add_next(int child_index);

Append a child node by index.

void pop_front();

Remove and unlink the first child.

void release();

Detach this node from its parent.

void clear();

Remove all children from this node.

Query

bool is_assigned() const;

Returns true if this node has a parent.

bool has_next() const;

Returns true if this node has at least one child.

int get_next() const;

Returns the index of the first child, or -1 if there are none.

int get_parent() const;

Returns the index of the parent node, or -1 if this is a root node.

int size() const;

Returns the number of direct children.

Iteration

for (int child_idx : tree[node_idx]) { /* ... */ }

Range-for over a node's direct children by index.

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Diagnostics

std::string to_string() const;

Returns an indented text representation of the full tree. Useful for debugging topology issues.