27 lines
396 B
Ruby
27 lines
396 B
Ruby
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require_relative 'singly_linked_list'
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class LinkedStack < LinkedList
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def empty?
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@length == 0
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end
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def push(data)
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new_head = Node.new(data)
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new_head.next = @head
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@length += 1
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@head = new_head
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end
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def pop
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return nil if empty?
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data = @head.data
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@head = @head.next
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@length -= 1
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data
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end
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def peek
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self[0]
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end
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end
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