Struct DiversifiedLateAcceptanceAcceptor 

pub struct DiversifiedLateAcceptanceAcceptor<S: PlanningSolution> { /* private fields */ }

Diversified late acceptance acceptor - combines late acceptance with best score tracking.

Extends [LateAcceptanceAcceptor] by also tracking the best score found. Accepts a move if it:

1. Improves the last step score (always accepted), OR
2. Is at least as good as the score from N steps ago, OR
3. Is within a tolerance of the best score found so far

The third condition allows escaping from local optima by accepting moves that don’t regress too far from the best known solution.

Example

use solverforge_solver::phase::localsearch::DiversifiedLateAcceptanceAcceptor;
use solverforge_core::score::SimpleScore;
use solverforge_core::domain::PlanningSolution;

#[derive(Clone)]
struct MySolution;
impl PlanningSolution for MySolution {
    type Score = SimpleScore;
    fn score(&self) -> Option<Self::Score> { None }
    fn set_score(&mut self, _: Option<Self::Score>) {}
}

// Accept if better than 400-step-old score OR within 5% of best
let acceptor = DiversifiedLateAcceptanceAcceptor::<MySolution>::new(400, 0.05);

Implementations

impl<S: PlanningSolution> DiversifiedLateAcceptanceAcceptor<S>

pub fn new(late_acceptance_size: usize, tolerance: f64) -> Self

Creates a new diversified late acceptance acceptor.

Arguments

• late_acceptance_size - Number of historical scores to keep. Must be > 0.
• tolerance - Fraction of best score to accept (0.05 = 5% tolerance)

Panics

Panics if late_acceptance_size is 0.

pub fn with_default_tolerance(late_acceptance_size: usize) -> Self

Creates with default tolerance of 0.01 (1%).

Trait Implementations

impl<S: PlanningSolution> Acceptor<S> for DiversifiedLateAcceptanceAcceptor<S>

fn is_accepted( &mut self, last_step_score: &S::Score, move_score: &S::Score, ) -> bool

Returns true if a move resulting in move_score should be accepted, given the previous step’s score.

fn phase_started(&mut self, initial_score: &S::Score)

Called when a phase starts.

fn step_ended(&mut self, step_score: &S::Score)

Called when a step ends with an accepted move.

fn phase_ended(&mut self)

Called when a phase ends.

fn step_started(&mut self)

Called when a step starts.

impl<S: PlanningSolution> Clone for DiversifiedLateAcceptanceAcceptor<S>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<S: PlanningSolution> Debug for DiversifiedLateAcceptanceAcceptor<S>

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

Formats the value using the given formatter.

impl<S: PlanningSolution> Default for DiversifiedLateAcceptanceAcceptor<S>

fn default() -> Self

Returns the “default value” for a type.