diff --git a/lib/linked_list.rb b/lib/linked_list.rb index 8dee5e8d..730daa25 100644 --- a/lib/linked_list.rb +++ b/lib/linked_list.rb @@ -19,43 +19,97 @@ def initialize # method to add a new node with the specific data value in the linked list # insert the new node at the beginning of the linked list def add_first(value) - raise NotImplementedError + current = @head + @head = Node.new(value, current) end # method to find if the linked list contains a node with specified value # returns true if found, false otherwise def search(value) - raise NotImplementedError + if @head.nil? + return false + else + current = @head + end + + while current + if current.data == value + return true + else + current = current.next + end + end end # method to return the max value in the linked list # returns the data value and not the node def find_max - raise NotImplementedError + return nil if @head.nil? + current = @head + max = @head.data + + while current + max = current.data if current.data > max + current = current.next + end end # method to return the min value in the linked list # returns the data value and not the node def find_min - raise NotImplementedError + return nil if @head.nil? + current = @head + min = @head.data + + while current + min = current.data if current.data < min + current = current.next + end end # method that returns the length of the singly linked list def length - raise NotImplementedError + count = 0 + node = @head + + return 0 if @head.nil? + + until node == nil + count += 1 + node = node.next + end + return count end # method that returns the value at a given index in the linked list # index count starts at 0 # returns nil if there are fewer nodes in the linked list than the index value def get_at_index(index) - raise NotImplementedError + return nil if @head.nil? + + current = @head + count = 0 + + until current.nil? + return current.data if count == index + count += 1 + current = current.next + end + + return nil end # method to print all the values in the linked list def visit - raise NotImplementedError + return nil if @head.nil? + current = @head + linked_list = "" + + while current + linked_list += "#{current.data}" + current = current.next + end end # method to delete the first node found with specified value