Class: ListaDoble

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/menu_dietetico/lista.rb

Overview

CLase que representa una lista doblemente enlazada

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ListaDoble

Returns a new instance of ListaDoble.



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# File 'lib/menu_dietetico/lista.rb', line 10

def initialize()
    @head = nil
    @tail = nil
end

Instance Attribute Details

#head ⇒ Object (readonly)

Returns the value of attribute head.



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# File 'lib/menu_dietetico/lista.rb', line 8

def head
  @head
end

#tail ⇒ Object (readonly)

Returns the value of attribute tail.



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# File 'lib/menu_dietetico/lista.rb', line 8

def tail
  @tail
end

Instance Method Details

#each ⇒ Object 



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# File 'lib/menu_dietetico/lista.rb', line 85

def each
    node = @head
    while(node != nil)
        yield node.value
        node = node.next
    end
end

#empty ⇒ Object 



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# File 'lib/menu_dietetico/lista.rb', line 15

def empty()
    vacio = false
    if (@head == nil)
        vacio = true
    elsif
        vacio == false
    end
    return vacio
end

#extract_head ⇒ Object 



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# File 'lib/menu_dietetico/lista.rb', line 47

def extract_head()
    if (empty())
        return nil
    elsif
        node = @head
        @head = @head.next
        node.next = nil
        node.prev = nil
        return node.value
    end
end

#extract_tail ⇒ Object 



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# File 'lib/menu_dietetico/lista.rb', line 59

def extract_tail()
    if (empty())
        return nil
    elsif
        node = @tail
        @tail = @tail.prev
        if (@tail)
            @tail.next = nil
        elsif
            @head == nil
        end
        node.next = nil
        node.prev = nil
        return node.value
    end
end

#insert_head(node) ⇒ Object 



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# File 'lib/menu_dietetico/lista.rb', line 25

def insert_head(node)
    if (empty())
        @head = node
        @tail = @head
    elsif
        @head.prev = node
        node.next = @head
        @head = node
    end
end

#insert_muchos(nodes) ⇒ Object 



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# File 'lib/menu_dietetico/lista.rb', line 76

def insert_muchos(nodes)
    i=0
    total=nodes.length
    while i<total do
        insert_head(nodes[i])
        i=i+1
    end
end

#insert_tail(node) ⇒ Object 



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# File 'lib/menu_dietetico/lista.rb', line 36

def insert_tail(node)
    if (empty())
        @head = node
        @tail = @head
    elsif
        @tail.next = node
        node.prev = @tail
        @tail = node
    end
end