Struct AdditionalKey 

pub struct AdditionalKey { /* private fields */ }

The Additional Key problem.

Given a set A of attributes, a set of functional dependencies F over A, a relation scheme R ⊆ A, and a set K of known candidate keys of R under F, determine whether R has a candidate key not in K.

A candidate key is a minimal subset X ⊆ R such that the closure of X under F contains all attributes of R.

Representation

Each attribute in R has a binary variable: x_i = 1 if the attribute is selected, 0 otherwise. A configuration is satisfying iff the selected attributes form a candidate key of R that is not in K.

Example

use problemreductions::models::misc::AdditionalKey;
use problemreductions::{Problem, Solver, BruteForce};

let problem = AdditionalKey::new(
    3,
    vec![(vec![0], vec![1, 2])],
    vec![0, 1, 2],
    vec![],
);
let solver = BruteForce::new();
let solution = solver.find_witness(&problem);
assert!(solution.is_some());

Implementations

impl AdditionalKey

pub fn new( num_attributes: usize, dependencies: Vec<(Vec<usize>, Vec<usize>)>, relation_attrs: Vec<usize>, known_keys: Vec<Vec<usize>>, ) -> Self

Create a new AdditionalKey instance.

Panics

Panics if any attribute index is >= num_attributes, or if relation_attrs contains duplicates.

pub fn num_attributes(&self) -> usize

Returns the number of attributes in the universal set A.

pub fn num_dependencies(&self) -> usize

Returns the number of functional dependencies.

pub fn num_relation_attrs(&self) -> usize

Returns the number of attributes in the relation scheme R.

pub fn num_known_keys(&self) -> usize

Returns the number of known candidate keys.

pub fn dependencies(&self) -> &[(Vec<usize>, Vec<usize>)]

Returns the functional dependencies.

pub fn relation_attrs(&self) -> &[usize]

Returns the relation scheme attributes.

pub fn known_keys(&self) -> &[Vec<usize>]

Returns the known candidate keys.

Trait Implementations

impl Clone for AdditionalKey

fn clone(&self) -> AdditionalKey

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AdditionalKey

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for AdditionalKey

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Problem for AdditionalKey

const NAME: &'static str = "AdditionalKey"

Base name of this problem type (e.g., “MaximumIndependentSet”).

type Value = Or

The evaluation value type.

fn variant() -> Vec<(&'static str, &'static str)>

Returns variant attributes derived from type parameters.

fn dims(&self) -> Vec<usize>

Configuration space dimensions. Each entry is the cardinality of that variable.

fn evaluate(&self, config: &[usize]) -> Or

Evaluate the problem on a configuration.

fn num_variables(&self) -> usize

Number of variables (derived from dims).

fn problem_type() -> ProblemType

Look up this problem’s catalog entry.

impl Serialize for AdditionalKey

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl DeclaredVariant for AdditionalKey