Progressive array combinations in Ruby

Progressive array combinations in Ruby

References

Reference NO 1

http://stackoverflow.com/questions/15190104/progressive-array-combinations-in-ruby

Reference NO 2

http://stackoverflow.com/questions/10924168/cartesian-product-of-array-with-itself-without-duplicates-in-ruby

Reference NO 3

http://stackoverflow.com/questions/5610461/ruby-combining-items-in-arrays

Reference NO 4

https://github.com/rubyworks/facets/blob/master/HISTORY.rdoc

Reference NO 5

http://shura.shu.ac.uk/952/1/fulltext.pdf

Reference NO 6

http://www.eventbrite.com/org/3151253436

Reference NO 7

http://www.rubykaren.com/project/index.php?option=com_content&view=article&id=172:schedule-locations&catid=3:classes-workshops&Itemid=14

Reference NO 8

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