86 lines
1.5 KiB
Ruby
86 lines
1.5 KiB
Ruby
# Refactor/rewrite this file
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class Node
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attr_accessor :value, :next
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def initialize(val, next_in_line)
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@value = val
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@next = next_in_line
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end
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end
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class LinkedList
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attr_accessor :head
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def initialize(val)
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@head = Node.new(val, nil)
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end
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def add(value)
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# Traverse to the end of the list
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# And insert a new node over there with the specified value
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current = @head
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current = current.next until current.next.nil?
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current.next = Node.new(value, nil)
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self
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end
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def delete(val)
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current = @head
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if current.value == val
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@head = @head.next
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else
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until current.next.nil?
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current = current.next
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if current.value == val
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current.value = current.next.value || nil
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current.next = current.next.next
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end
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end
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end
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@head
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end
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end
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def list_palindrome(list)
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stack = []
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current = list.head
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while current
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stack.push(current.value)
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current = current.next
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end
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current = list.head
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while current
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stack_temp = stack.pop
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return false unless current.value == stack_temp
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current = current.next
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end
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true
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end
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def list_check(list)
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return false unless list
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stack = []
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slow = fast = list.head
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while fast && !fast.next.nil?
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fast = fast.next.next
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stack.push(slow.value)
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slow = slow.next
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end
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slow = slow.next unless fast.nil?
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until slow.nil?
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temp = stack.pop
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return false unless slow.value == temp
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slow = slow.next
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end
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true
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end
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