Struct RandomTieBreaker 

pub struct RandomTieBreaker<Var, Value> { /* private fields */ }

A tie breaker which selects the variable with the “best” value (according to the Direction), if there is a tie then it will select any of the variables part of this tie with equal probability.

The random selection proceeds as follows:

• If no variable has been considered yet then this is the one which is currently considered to be selected
• If a variable has previously been considered then we can split into 3 cases:
  • If the direction is Direction::Maximum and the value of the newly provided variable is stricly bigger than that of the currently selected variable then we update the currently selected variable
  • If the direction is Direction::Minimum and the value of the newly provided variable is stricly smaller than that of the currently selected variable then we update the currently selected variable
  • If the values are equal then we randomly select the newly considered variable with probability 1 / num_previously_seen_variables where num_previously_seen_variables is the number of variables which have been previously considered with the same value

Implementations

impl<Var, Value> RandomTieBreaker<Var, Value>

pub fn new( direction: Direction, rng: Box<dyn Random>, ) -> RandomTieBreaker<Var, Value>

Trait Implementations

impl<Var, Value> Debug for RandomTieBreaker<Var, Value>

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

Formats the value using the given formatter.

impl<Var, Value> TieBreaker<Var, Value> for RandomTieBreaker<Var, Value>

where Var: Copy, Value: PartialOrd,

fn consider(&mut self, variable: Var, value: Value)

Consider the next additional element with corresponding value

fn select(&mut self) -> Option<Var>

Get the final variable which was selected. After this method is called it resets the stored values such that it can be used again. This resetting is done to prevent the tie-breaker from returning a variable which has a value which is out-of-date.

fn get_direction(&self) -> Direction

Returns whether the tie-breaker is attempting to find the minimum (Direction::Minimum) or maximum (Direction::Maximum) element.