Struct MinimumRegisterSufficiencyForLoops 

pub struct MinimumRegisterSufficiencyForLoops { /* private fields */ }

The Minimum Register Sufficiency for Loops problem.

Given a loop of length N (representing N timesteps arranged in a circle) and a set of variables, each active during a contiguous circular arc of timesteps specified by (start_time, duration), assign a register index to each variable such that:

• No two variables with overlapping circular arcs share the same register
• The number of distinct registers used is minimized

This is equivalent to the circular arc graph coloring problem, where each variable corresponds to a circular arc and registers correspond to colors.

Representation

Each variable is assigned a register index from {0, ..., n-1} where n is the number of variables. The configuration config[i] gives the register assigned to variable i.

Example

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

// 3 variables on a loop of length 6, all pairs conflict
let problem = MinimumRegisterSufficiencyForLoops::new(
    6,
    vec![(0, 3), (2, 3), (4, 3)],
);
let solver = BruteForce::new();
let solution = solver.find_witness(&problem);
assert!(solution.is_some());
let val = problem.evaluate(&solution.unwrap());
assert_eq!(val, Min(Some(3)));

Implementations

impl MinimumRegisterSufficiencyForLoops

pub fn new(loop_length: usize, variables: Vec<(usize, usize)>) -> Self

Create a new Minimum Register Sufficiency for Loops instance.

Panics

Panics if loop_length is zero, if any duration is zero or exceeds loop_length, or if any start_time >= loop_length.

pub fn loop_length(&self) -> usize

Get the loop length N.

pub fn num_variables(&self) -> usize

Get the number of variables.

pub fn variables(&self) -> &[(usize, usize)]

Get the variables as (start_time, duration) pairs.

Trait Implementations

impl Clone for MinimumRegisterSufficiencyForLoops

fn clone(&self) -> MinimumRegisterSufficiencyForLoops

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MinimumRegisterSufficiencyForLoops

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MinimumRegisterSufficiencyForLoops

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Problem for MinimumRegisterSufficiencyForLoops

const NAME: &'static str = "MinimumRegisterSufficiencyForLoops"

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

type Value = Min<usize>

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]) -> Min<usize>

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 MinimumRegisterSufficiencyForLoops

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 MinimumRegisterSufficiencyForLoops