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76 lines
1.2 KiB
Ruby
76 lines
1.2 KiB
Ruby
# 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 StackAsArray < Stack
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def initialize(size = 0)
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super()
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@array = Array.new(size)
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end
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def purge
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while @count > 0
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@count -= 1
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@array[@count] = nil
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end
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end
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def push(obj)
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raise ContainerFull if @count == @array.length
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@array[@count] = obj
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@count += 1
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end
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def pop
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raise ContainerEmpty if @count == 0
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@count -= 1
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result = @array[@count]
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@array[@count] = nil
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return result
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end
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def top
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raise ContainerEmpty if @count == 0
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return @array[@count - 1]
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end
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def each
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for i in 0 ... @count
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yield @array[i]
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end
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end
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attr_reader :array
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class Iterator < Opus8::Iterator
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def initialize(stack)
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@stack = stack
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@position = 0
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end
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def more?
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@position < @stack.count
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end
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def succ
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if more?
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assert { more? }
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result = @stack.array[@position]
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@position += 1
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else
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result = nil
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end
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return result
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end
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end
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def iter
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Iterator.new(self)
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end
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end |