#
# This file contains the Ruby code from Program 4.6 of
# "Data Structures and Algorithms
# with Object-Oriented Design Patterns in Ruby"
# by Bruno R. Preiss.
#
# Copyright (c) 2004 by Bruno R. Preiss, P.Eng.  All rights reserved.
#
# http://www.brpreiss.com/books/opus8/programs/pgm04_06.txt
#
class MultiDimensionalArray

    def getOffset(indices)
	raise IndexError if indices.length != @dimensions.length
        offset = 0
	for i in 0 ... @dimensions.length
            if indices[i] < 0 or indices[i] >= @dimensions[i]
                raise IndexError
	    end
            offset += @factors[i] * indices[i]
	end
        return offset
    end

    def [](*indices)
        @data[self.getOffset(indices)]
    end

    def []=(*indicesAndValue)
	value = indicesAndValue.pop
        @data[self.getOffset(indicesAndValue)] = value
    end

end