Struct LoudsTree 

pub struct LoudsTree { /* private fields */ }

LOUDS-encoded tree with O(1) navigation.

Stores the tree structure in 2n+1 bits plus rank superblocks for fast rank/select queries.

Implementations

impl LoudsTree

pub fn from_degrees(degrees: &[usize]) -> Self

Build a LOUDS tree from BFS-order degree sequence.

degrees[i] is the number of children of the i-th node in level-order. The root is degrees[0].

Panics

Panics if the degree sequence is empty or inconsistent (doesn’t describe a valid tree).

pub fn from_children(children: &[&[usize]]) -> Self

Build a LOUDS tree from a pointer-based tree (children list per node).

children[i] is a slice of child node indices for node i. Nodes must be numbered 0..n in BFS order.

Panics

Panics if the tree structure is inconsistent.

pub fn node_count(&self) -> usize

Number of nodes in the tree.

pub fn is_empty(&self) -> bool

Whether the tree is empty (no nodes).

pub fn size_in_bytes(&self) -> usize

Total memory usage in bytes (excluding struct overhead).

pub fn degree(&self, v: usize) -> usize

Degree (number of children) of node v.

Panics

Panics if v >= node_count().

pub fn parent(&self, v: usize) -> Option<usize>

Parent of node v, or None for the root (node 0).

Panics

Panics if v >= node_count().

pub fn first_child(&self, v: usize) -> Option<usize>

First child of node v, or None if v is a leaf.

Panics

Panics if v >= node_count().

pub fn next_sibling(&self, v: usize) -> Option<usize>

Next sibling of node v, or None if v is the last child.

Panics

Panics if v >= node_count().

pub fn is_leaf(&self, v: usize) -> bool

Whether node v is a leaf (has no children).

Panics

Panics if v >= node_count().

pub fn depth(&self, v: usize) -> usize

Depth of node v (root has depth 0).

This is O(depth) — it walks to the root via parent().

Panics

Panics if v >= node_count().

pub fn children(&self, v: usize) -> ChildIter<'_>

Iterator over children of node v.

Panics

Panics if v >= node_count().

pub fn subtree_size(&self, v: usize) -> usize

Subtree size rooted at node v (including v itself).

This is O(subtree_size) — it performs a BFS within the subtree.

Panics

Panics if v >= node_count().

Trait Implementations

impl Clone for LoudsTree

fn clone(&self) -> LoudsTree

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LoudsTree

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.