/
linked_list.rb
190 lines (171 loc) · 4.16 KB
/
linked_list.rb
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class LinkedList
@@nodes=[]
@@tempo=[]
def initialize
puts "Init ..."
end
def append(num)
@@tempo.push(num)
node=Node.new(num)
@@nodes.push(node)
if @@nodes.length>1
@@nodes[@@nodes.length-2].next_node=node
end
end
def prepend(num)
head=@@nodes[0]
node=Node.new(num)
node.next_node=head
temp_nodes=[]
temp_nodes[0]=node
for i in 1..@@nodes.length
temp_nodes[i]=@@nodes[i-1]
end
@@nodes=temp_nodes
end
def size
return @@nodes.length
end
def head
if @@nodes.empty?
puts "The list is empty"
return
else
puts "The value of first node is : #{@@nodes[0].value}"
return @@nodes[0]
end
end
def tail
if @@nodes.empty?
puts "The list is empty"
return
else
puts "The value of last node is : #{@@nodes[@@nodes.length-1].value}"
return @@nodes[@@nodes.length-1]
end
end
def at(index)
if @@nodes.length-1 < index
puts "The number is out of bounds"
return
else
puts "The value of the node at index #{index} is #{@@nodes[index].value}"
return @@nodes[index]
end
end
def pop
last_node=@@nodes.length-1
@@nodes=@@nodes.slice(0,last_node)
@@nodes[last_node-1].next_node=nil
end
def contains?(value)
for i in 0..@@nodes.length-1
if @@nodes[i].value==value
return true
end
end
return false
end
def find(value)
for i in 0..@@nodes.length-1
if @@nodes[i].value==value
return i
end
end
return nil
end
def to_s
string=""
for i in 0..@@nodes.length-1
string +="("
string += @@nodes[i].value.to_s
string += ")"
unless i == @@nodes.length-1
string += " -> "
end
end
return string
end
def insert_at(value, index)
if index>@@nodes.length
puts "The index is out of range"
return
end
node=Node.new(value)
temp_nodes=[]
for i in 0..index-1
temp_nodes[i]=@@nodes[i]
end
temp_nodes[index]=node
for i in index..@@nodes.length-1
temp_nodes[i+1]=@@nodes[i]
end
if index<@@nodes.length
temp_nodes[index].next_node=temp_nodes[index+1]
else
temp_nodes[index].next_node=nil
end
unless index==0
temp_nodes[index-1].next_node=node
end
@@nodes=temp_nodes
end
def remove_at(index)
if index>=@@nodes.length
puts "The index is out of range"
return
end
temp_nodes=[]
for i in 0..index-1
temp_nodes[i]=@@nodes[i]
end
for i in index..@@nodes.length-2
temp_nodes[i]=@@nodes[i+1]
end
if index=@@nodes.length-1
temp_nodes[temp_nodes.length-1].next_node=nil
elsif index>0
temp_nodes[index-1].next_node=temp_nodes[index]
end
@@nodes=temp_nodes
end
end
class Node
attr_accessor :value
attr_accessor :next_node
def initialize(value)
@value = value
@next_node = nil
end
end
llist=LinkedList.new()
puts "Added three elements 44,55 and 66"
llist.append(44)
llist.append(55)
llist.append(66)
puts llist
puts "Prepended element 99"
llist.prepend(99)
puts llist
puts "Size of the linked list is #{llist.size}"
llist.head
llist.tail
llist.at(2)
puts "Appending element 77"
llist.append(77)
puts llist
puts "Popping element 77"
llist.pop
puts llist
puts "Does it contain 77? #{llist.contains?(77)}"
puts "Does it contain 55? #{llist.contains?(55)}"
puts "Index of 55 is #{llist.find(55)}"
puts "Inserting element 88 at index 7"
llist.insert_at(88,7)
puts llist
puts "Inserting element 88 at index 4"
llist.insert_at(88,4)
puts llist
puts "Removing element at index 0"
llist.remove_at(0)
puts llist