MapOfAlphaToNumber = 1.upto(26).inject([{}, 'A']) { |(hash, alpha), number|
	[hash.merge(alpha => number), alpha.succ]
}[0]
 
 
def parse_excel_row_id(string)
	string.split(//).inject(0) { |row_num, alpha|
		raise 'Invalid Row ID' unless MapOfAlphaToNumber.has_key?(alpha)
 
		row_num * 26 + MapOfAlphaToNumber[alpha]
	}
end
 
 
printf "'A'   --> %d", parse_excel_row_id('A')
puts
printf "'AA'  --> %d", parse_excel_row_id('AA')
puts
printf "'ZZZ' --> %d", parse_excel_row_id('ZZZ')
puts
 

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