# algograph

Directed or undirected graphs and their algorithms implemented in Rust.

## Low-level graphs and tagged graphs

Some graph libraries allow customized types of vertices and edges.
But for algorithm authors, these customized types are hard to deal with.
Can we copy a vertex?
What is the cost of doing that copying?

In this crate, there are traits and implementations of low level graphs.
Vertices and edges in low level graphs are lightweight ID's.
They are essentially `usize`.
Algorithm authors may feel free to copy and store these ID's.

Based on low-level graphs, for convenience,
there are also traits and a naive implementation
to support graphs with customized vertex types and edge types.
They are under `tagged` module.

## `ShadowedSubgraph` and `SelectedSubgraph`

They can form subgraphs with shadowed/selected vertices and edges.
Futhermore, these subgraphs are shrinkable.
While they are shrinking, their underlying graphs are kept unchanged.