pulau-rs

2 unstable releases

0.2.0	Jan 10, 2023
0.1.0	Dec 6, 2022

#463 in Embedded development

MIT license

50KB
846 lines

allocation-free union-find library for bare metal environments

The library provides the following algorithms that is used with UnionFind.

QuickFind
QuickUnion
Weighted QuickUnion
Weighted QuickUnion With Path Compression (Default)

Setup

Cargo.toml setup

[dependencies]
pulau-rs = "0.2.0"

Asymptotic Complexity

Algorithm	Struct	Init	Union	Find	Connected
QuickFind	`QuickFind`	`O(N)`	`O(N)`	`O(1)`	`O(1)`
QuickUnion	`QuickUnion<false, false>`	`O(N)`	`O(N)`	`O(N)`	`O(N)`
Weighted QuickUnion	`QuickUnion<ByRank, false>`	`O(N)`	`O(lg N)`	`O(lg N)`	`O(lg N)`
Weighted (Rank) QuickUnion With Path Compression	`QuickUnion<ByRank, true>`	`O(N)`	`Θ(α(N))`	`Θ(α(N))`	`Θ(α(N))`
Weighted (Size) QuickUnion With Path Compression	`QuickUnion<BySize, true>`	`O(N)`	`Θ(α(N))`	`Θ(α(N))`	`Θ(α(N))`

*Where α is the inverse Ackermann function

Applications of UnionFind

Checking for connected components in a graph
Checking for cycles in a graph
Searching for connected components in an image
Finding minimum spanning tree using Kruskal

Example Usage

use pulau_rs::{UnionFind, QuickFind, QuickUnion, BySize};
fn make_uf_quickfind() {
    // construct with quickfind algorithm with fixed size 10
    let mut uf = UnionFind::<QuickFind, u32, 10, 0>::new();
}

fn make_uf_quickunion() {
    // construct weighted quickunion with path compression algorithm with fixed size 10
    let mut uf = UnionFind::<QuickUnion, u32, 10>::new();
    // construct weighted quickunion with path compression using size heuristics and fixed size 10
    let mut uf_with_sz = UnionFind::<QuickUnion<BySize>, u8, 10>::new();
    uf.union_sets(1,2);
    uf.union_sets(2,3);
    uf.union_sets(2,3);
    assert!(uf.connected(1, 3));
}

License

pulau-rs is licensed under MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

no-std pulau-rs