-
Notifications
You must be signed in to change notification settings - Fork 150
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
1 parent
87ee124
commit bd72ea2
Showing
5 changed files
with
414 additions
and
282 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,316 @@ | ||
// Licensed under the Apache License, Version 2.0 (the "License"); you may | ||
// not use this file except in compliance with the License. You may obtain | ||
// a copy of the License at | ||
// | ||
// http://www.apache.org/licenses/LICENSE-2.0 | ||
// | ||
// Unless required by applicable law or agreed to in writing, software | ||
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT | ||
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the | ||
// License for the specific language governing permissions and limitations | ||
// under the License. | ||
|
||
use std::hash::Hash; | ||
|
||
use petgraph::data::{Build, Create}; | ||
use petgraph::visit::{Data, NodeIndexable}; | ||
|
||
use super::InvalidInputError; | ||
|
||
/// Generate an undirected heavy hex graph. Fig. 2 of | ||
/// https://arxiv.org/abs/1907.09528 | ||
/// An ASCII diagram of the graph is given by: | ||
/// | ||
/// .. note:: | ||
/// | ||
/// ... D-S-D D ... | ||
/// | | | | ||
/// ...-F F-S-F ... | ||
/// | | | | ||
/// ... D D D ... | ||
/// | | | | ||
/// ... F-S-F F-... | ||
/// | | | | ||
/// ......... | ||
/// | | | | ||
/// ... D D D ... | ||
/// | | | | ||
/// ...-F F-S-F ... | ||
/// | | | | ||
/// ... D D D ... | ||
/// | | | | ||
/// ... F-S-F F-... | ||
/// | | | | ||
/// ......... | ||
/// | | | | ||
/// ... D D D ... | ||
/// | | | | ||
/// ...-F F-S-F ... | ||
/// | | | | ||
/// ... D D D ... | ||
/// | | | | ||
/// ... F-S-F F-... | ||
/// | | | | ||
/// ... D D-S-D ... | ||
/// | ||
/// | ||
/// * `d` - Distance of the code. If ``d`` is set to ``1`` a graph with a | ||
/// single node will be returned. d must be an odd number. | ||
/// * `default_node_weight` - A callable that will return the weight to use | ||
/// for newly created nodes. This is ignored if `weights` is specified, | ||
/// as the weights from that argument will be used instead. | ||
/// * `default_edge_weight` - A callable that will return the weight object | ||
/// to use for newly created edges. | ||
/// * `bidirectional` - Whether edges are added bidirectionally, if set to | ||
/// `true` then for any edge `(u, v)` an edge `(v, u)` will also be added. | ||
/// If the graph is undirected this will result in a pallel edge. | ||
/// | ||
/// # Example | ||
/// ```rust | ||
/// use rustworkx_core::petgraph; | ||
/// use rustworkx_core::generators::heavy_hex_graph; | ||
/// use rustworkx_core::petgraph::visit::EdgeRef; | ||
/// | ||
/// let expected_edge_list = vec![ | ||
/// (0, 13), | ||
/// (1, 13), | ||
/// (1, 14), | ||
/// (2, 14), | ||
/// (3, 15), | ||
/// (4, 15), | ||
/// (4, 16), | ||
/// (5, 16), | ||
/// (6, 17), | ||
/// (7, 17), | ||
/// (7, 18), | ||
/// (8, 18), | ||
/// (0, 9), | ||
/// (3, 9), | ||
/// (5, 12), | ||
/// (8, 12), | ||
/// (10, 14), | ||
/// (10, 16), | ||
/// (11, 15), | ||
/// (11, 17), | ||
/// ]; | ||
/// let d = 3; | ||
/// let g: petgraph::graph::UnGraph<(), ()> = heavy_hex_graph(d, || (), || (), false).unwrap(); | ||
/// assert_eq!(g.node_count(), (5 * d * d - 2 * d - 1) / 2); | ||
/// assert_eq!(g.edge_count(), 2 * d * (d - 1) + (d + 1) * (d - 1)); | ||
/// assert_eq!( | ||
/// expected_edge_list, | ||
/// g.edge_references() | ||
/// .map(|edge| (edge.source().index(), edge.target().index())) | ||
/// .collect::<Vec<(usize, usize)>>(), | ||
/// ) | ||
/// ``` | ||
pub fn heavy_hex_graph<G, T, F, H, M>( | ||
d: usize, | ||
mut default_node_weight: F, | ||
mut default_edge_weight: H, | ||
bidirectional: bool, | ||
) -> Result<G, InvalidInputError> | ||
where | ||
G: Build + Create + Data<NodeWeight = T, EdgeWeight = M> + NodeIndexable, | ||
F: FnMut() -> T, | ||
H: FnMut() -> M, | ||
G::NodeId: Eq + Hash, | ||
{ | ||
if d % 2 == 0 { | ||
return Err(InvalidInputError {}); | ||
} | ||
let num_nodes = (5 * d * d - 2 * d - 1) / 2; | ||
let num_edges = 2 * d * (d - 1) + (d + 1) * (d - 1); | ||
let mut graph = G::with_capacity(num_nodes, num_edges); | ||
|
||
if d == 1 { | ||
graph.add_node(default_node_weight()); | ||
return Ok(graph); | ||
} | ||
let num_data = d * d; | ||
let num_syndrome = (d - 1) * (d + 1) / 2; | ||
let num_flag = d * (d - 1); | ||
|
||
let nodes_data: Vec<G::NodeId> = (0..num_data) | ||
.map(|_| graph.add_node(default_node_weight())) | ||
.collect(); | ||
let nodes_syndrome: Vec<G::NodeId> = (0..num_syndrome) | ||
.map(|_| graph.add_node(default_node_weight())) | ||
.collect(); | ||
let nodes_flag: Vec<G::NodeId> = (0..num_flag) | ||
.map(|_| graph.add_node(default_node_weight())) | ||
.collect(); | ||
|
||
// connect data and flags | ||
for (i, flag_chunk) in nodes_flag.chunks(d - 1).enumerate() { | ||
for (j, flag) in flag_chunk.iter().enumerate() { | ||
graph.add_edge(nodes_data[i * d + j], *flag, default_edge_weight()); | ||
graph.add_edge(nodes_data[i * d + j + 1], *flag, default_edge_weight()); | ||
if bidirectional { | ||
graph.add_edge(*flag, nodes_data[i * d + j], default_edge_weight()); | ||
graph.add_edge(*flag, nodes_data[i * d + j + 1], default_edge_weight()); | ||
} | ||
} | ||
} | ||
|
||
// connect data and syndromes | ||
for (i, syndrome_chunk) in nodes_syndrome.chunks((d + 1) / 2).enumerate() { | ||
if i % 2 == 0 { | ||
graph.add_edge(nodes_data[i * d], syndrome_chunk[0], default_edge_weight()); | ||
graph.add_edge( | ||
nodes_data[(i + 1) * d], | ||
syndrome_chunk[0], | ||
default_edge_weight(), | ||
); | ||
if bidirectional { | ||
graph.add_edge(syndrome_chunk[0], nodes_data[i * d], default_edge_weight()); | ||
graph.add_edge( | ||
syndrome_chunk[0], | ||
nodes_data[(i + 1) * d], | ||
default_edge_weight(), | ||
); | ||
} | ||
} else if i % 2 == 1 { | ||
graph.add_edge( | ||
nodes_data[i * d + (d - 1)], | ||
syndrome_chunk[syndrome_chunk.len() - 1], | ||
default_edge_weight(), | ||
); | ||
graph.add_edge( | ||
nodes_data[i * d + (2 * d - 1)], | ||
syndrome_chunk[syndrome_chunk.len() - 1], | ||
default_edge_weight(), | ||
); | ||
if bidirectional { | ||
graph.add_edge( | ||
syndrome_chunk[syndrome_chunk.len() - 1], | ||
nodes_data[i * d + (d - 1)], | ||
default_edge_weight(), | ||
); | ||
graph.add_edge( | ||
syndrome_chunk[syndrome_chunk.len() - 1], | ||
nodes_data[i * d + (2 * d - 1)], | ||
default_edge_weight(), | ||
); | ||
} | ||
} | ||
} | ||
|
||
// connect flag and syndromes | ||
for (i, syndrome_chunk) in nodes_syndrome.chunks((d + 1) / 2).enumerate() { | ||
if i % 2 == 0 { | ||
for (j, syndrome) in syndrome_chunk.iter().enumerate() { | ||
if j != 0 { | ||
graph.add_edge( | ||
*syndrome, | ||
nodes_flag[i * (d - 1) + 2 * (j - 1) + 1], | ||
default_edge_weight(), | ||
); | ||
graph.add_edge( | ||
*syndrome, | ||
nodes_flag[(i + 1) * (d - 1) + 2 * (j - 1) + 1], | ||
default_edge_weight(), | ||
); | ||
if bidirectional { | ||
graph.add_edge( | ||
nodes_flag[i * (d - 1) + 2 * (j - 1) + 1], | ||
*syndrome, | ||
default_edge_weight(), | ||
); | ||
graph.add_edge( | ||
nodes_flag[(i + 1) * (d - 1) + 2 * (j - 1) + 1], | ||
*syndrome, | ||
default_edge_weight(), | ||
); | ||
} | ||
} | ||
} | ||
} else if i % 2 == 1 { | ||
for (j, syndrome) in syndrome_chunk.iter().enumerate() { | ||
if j != syndrome_chunk.len() - 1 { | ||
graph.add_edge( | ||
*syndrome, | ||
nodes_flag[i * (d - 1) + 2 * j], | ||
default_edge_weight(), | ||
); | ||
graph.add_edge( | ||
*syndrome, | ||
nodes_flag[(i + 1) * (d - 1) + 2 * j], | ||
default_edge_weight(), | ||
); | ||
if bidirectional { | ||
graph.add_edge( | ||
nodes_flag[i * (d - 1) + 2 * j], | ||
*syndrome, | ||
default_edge_weight(), | ||
); | ||
graph.add_edge( | ||
nodes_flag[(i + 1) * (d - 1) + 2 * j], | ||
*syndrome, | ||
default_edge_weight(), | ||
); | ||
} | ||
} | ||
} | ||
} | ||
} | ||
Ok(graph) | ||
} | ||
|
||
#[cfg(test)] | ||
mod tests { | ||
use crate::generators::heavy_hex_graph; | ||
use crate::generators::InvalidInputError; | ||
use crate::petgraph; | ||
use crate::petgraph::visit::EdgeRef; | ||
|
||
#[test] | ||
fn test_heavy_hex_graph_3() { | ||
let expected_edge_list = vec![ | ||
(0, 13), | ||
(1, 13), | ||
(1, 14), | ||
(2, 14), | ||
(3, 15), | ||
(4, 15), | ||
(4, 16), | ||
(5, 16), | ||
(6, 17), | ||
(7, 17), | ||
(7, 18), | ||
(8, 18), | ||
(0, 9), | ||
(3, 9), | ||
(5, 12), | ||
(8, 12), | ||
(10, 14), | ||
(10, 16), | ||
(11, 15), | ||
(11, 17), | ||
]; | ||
let d = 3; | ||
let g: petgraph::graph::UnGraph<(), ()> = heavy_hex_graph(d, || (), || (), false).unwrap(); | ||
assert_eq!(g.node_count(), (5 * d * d - 2 * d - 1) / 2); | ||
assert_eq!(g.edge_count(), 2 * d * (d - 1) + (d + 1) * (d - 1)); | ||
assert_eq!( | ||
expected_edge_list, | ||
g.edge_references() | ||
.map(|edge| (edge.source().index(), edge.target().index())) | ||
.collect::<Vec<(usize, usize)>>(), | ||
); | ||
} | ||
|
||
#[test] | ||
fn test_heavy_hex_error() { | ||
let d = 2; | ||
match heavy_hex_graph::<petgraph::graph::DiGraph<(), ()>, (), _, _, ()>( | ||
d, | ||
|| (), | ||
|| (), | ||
false, | ||
) { | ||
Ok(_) => panic!("Returned a non-error"), | ||
Err(e) => assert_eq!(e, InvalidInputError), | ||
}; | ||
} | ||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.