67 lines
1.5 KiB
Ruby
67 lines
1.5 KiB
Ruby
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# This file contains the Ruby code from book of
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# "Data Structures and Algorithms
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# with Object-Oriented Design Patterns in Ruby"
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# by Bruno R. Preiss.
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#
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# Copyright (c) 2004 by Bruno R. Preiss, P.Eng. All rights reserved.
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class BTree < MWayTree
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def initialize(m)
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super
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@parent = nil
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end
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def attachSubtree(i, t)
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@subtree[i] = t
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t.parent = self
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end
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attr_accessor :parent
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def insert(obj)
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if empty?
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if @parent.nil?
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attachSubtree(0, BTree.new(m))
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@key[1] = obj
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attachSubtree(1, BTree.new(m))
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@count = 1
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else
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@parent.insertUp(obj, BTree.new(m))
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end
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else
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index = findIndex(obj)
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raise ArgumentError if index != 0 and @key == obj
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@subtree[index].insert(obj)
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end
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end
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def insertUp(obj, child)
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index = findIndex(obj)
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if not full?
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insertPair(index + 1, obj, child)
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@count = @count + 1
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else
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extraKey, extraTree = insertPair(index+1, obj, child)
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if @parent.nil?
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left = BTree.new(m)
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right = BTree.new(m)
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left.attachLeftHalfOf(self)
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right.attachRightHalfOf(self)
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right.insertUp(extraKey, extraTree)
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attachSubtree(0, left)
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@key[1] = @key[(m + 1)/2]
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attachSubtree(1, right)
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@count = 1
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else
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@count = (m + 1)/2 - 1
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right = BTree.new(m)
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right.attachRightHalfOf(self)
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right.insertUp(extraKey, extraTree)
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@parent.insertUp(@key[(m + 1)/2], right)
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end
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end
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end
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end
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