Class: DS::Queue

Inherits:
Object
  • Object
show all
Defined in:
lib/ds/queues/queue.rb

Overview

Class implements queue data structure.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(store = :array) ⇒ Queue

Create new queue. First parameter determines how the queue will be represented internally.



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# File 'lib/ds/queues/queue.rb', line 8

def initialize(store = :array)
  if store == :array 
    @store = []
  else
    @store = List.new
  end
end

Class Method Details

.create ⇒ Object

Create new queue.Internaly uses list to store elements.



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# File 'lib/ds/queues/queue.rb', line 17

def Queue.create
  new(:list)
end

Instance Method Details

#dequeue ⇒ Object Also known as: shift

Removes element from queue and returns it.



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# File 'lib/ds/queues/queue.rb', line 30

def dequeue
  @store.shift
end

#empty? ⇒ Boolean

Checks if queue is empty.

Returns:

  • (Boolean) 


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# File 'lib/ds/queues/queue.rb', line 47

def empty?
  @store.empty?
end

#enqueue(x) ⇒ Object Also known as: push

Adds element to queue and returns queue itself.



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# File 'lib/ds/queues/queue.rb', line 22

def enqueue(x)
  @store << x
  self
end

#length ⇒ Object

Returns length of queue. If queue is empty returns 0.



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# File 'lib/ds/queues/queue.rb', line 42

def length
  @store.length
end

#peek ⇒ Object

Returns element from forehead of queue.



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# File 'lib/ds/queues/queue.rb', line 37

def peek
  @store.first
end