Class: LinkedList::Singly

Inherits:
Object
  • Object
show all
Defined in:
lib/data_struct/linked_list.rb

Overview

This is a singly linked list implementation.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Singly

Returns a new instance of Singly.



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# File 'lib/data_struct/linked_list.rb', line 27

def initialize
  @head = nil
  @length = 0
end

Instance Attribute Details

#head ⇒ Object (readonly)

Returns the value of attribute head.



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# File 'lib/data_struct/linked_list.rb', line 26

def head
  @head
end

#length ⇒ Object (readonly)

Returns the value of attribute length.



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# File 'lib/data_struct/linked_list.rb', line 26

def length
  @length
end

Instance Method Details

#each ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 83

def each
  node = @head
  arr = []
  @length.times do
    arr << yield(node.data)
    node = node.next_val
  end
  arr
end

#index(index_val) ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 93

def index(index_val)
  raise 'index value higher than current length of list' if @length - 1 < index_val

  node = @head
  index_val.times do
    node = node.next_val
  end
  node.data
end

#index_of(val) ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 103

def index_of(val)
  node = @head
  @length.times do
    return node.data if node.data == val

    node = node.next_val
  end
  raise 'value not found'
end

#pop ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 48

def pop
  node = @head
  if @length.zero?
    raise 'Error: List is empty'
  else
    de_length
    (@length - 1).times do
      node = node.next_val
    end
    node.next_val = nil
  end

  @head
end

#push(val) ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 37

def push(val)
  in_length
  return @head = SinglyNode.new(val) if @head.nil?

  node = @head
  (@length - 2).times do
    node = node.next_val
  end
  node.next_val = SinglyNode.new val
end

#to_a ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 73

def to_a
  node = @head
  arr = []
  @length.times do
    arr << node.data
    node = node.next_val
  end
  arr
end

#to_s ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 63

def to_s
  node = @head
  str = ''
  (@length - 1).times do
    str += "#{node.data} "
    node = node.next_val
  end
  str
end

#unshift(val) ⇒ Object 



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# File 'lib/data_struct/linked_list.rb', line 32

def unshift(val)
  in_length
  @head = SinglyNode.new val, @head
end