Никола обнови решението на 11.01.2016 15:34 (преди над 8 години)
+module SpreadSheetHelper
+ FORMULAS = ['ADD', 'MULTIPLY', 'SUBTRACT', 'DIVIDE', 'MOD']
+ INFORMATION = {'ADD': [2, 'ge', :+], 'MULTIPLY': [2, 'ge', :*],
+ 'SUBTRACT': [2, 'eq', :-], 'DIVIDE': [2, 'eq', :/],
+ 'MOD': [2, 'eq', :%]}
+ ERRORS = {'eq': ""}
+
+ def is_cell_reference? (index)
+ true if parse_index index rescue false
+ end
+
+ def is_number?(item)
+ true if Float(item) rescue false
+ end
+
+ def parse_sheet(sheet)
+ rows = sheet.split("\n").select { |item| ! (item =~ /^\s*$/) }.map(&:strip)
+ rows.map { |row| row.split(/\t|(?:\ {2,})/) }
+ end
+
+ def parse_formula(item)
+ formula = /^\ *([A-Z]+)\((.+)\)$/.match(item)
+ raise self.class::Error, "Invalid expression '#{item}'" if formula.nil?
+ formula_name, parameters = formula.captures
+ parameters = evaluate_formula_parameters parameters.split(',').map(&:strip)
+ validate_formula INFORMATION[formula_name.to_sym], formula_name, parameters
+ evaluate_formula INFORMATION[formula_name.to_sym], formula_name, parameters
+ end
+
+ def validate_formula(info, formula_name, parameters)
+ if ! FORMULAS.include? formula_name
+ raise self.class::Error, "Unknown function '#{formula_name}'"
+ else
+ validate_formula_helper info, formula_name, parameters
+ end
+ end
+
+ def validate_formula_helper(info, formula_name, parameters)
+ if parameters.length != info[0] && info[1] == 'eq'
+ raise self.class::Error, "Wrong number of arguments for '#{formula_name}'\
+: expected #{info[0]}, got #{parameters.length}"
+ elsif parameters.length < info[0] && info[1] == 'ge'
+ raise self.class::Error, "Wrong number of arguments for '#{formula_name}'\
+: expected at least #{info[0]}, got #{parameters.length}"
+ end
+ end
+
+ def evaluate_formula (info, formula_name, parameters)
+ if info[1] == 'ge'
+ result = parameters.reduce(&info[2])
+ else
+ result = parameters[0].public_send info[2], parameters[1]
+ end
+ if result == result.floor
+ result.to_i.to_s
+ else
+ '%.2f' % result
+ end
+ end
+
+ def parse_index(index)
+ parsed_index = /^([A-Z]+)([0-9]+)$/.match(index)
+ raise self.class::Error, "Invalid cell index '#{index}'"if parsed_index.nil?
+ col = parsed_index[1].split("").reverse.map.with_index do |char, power|
+ (char.ord - 64) * (26 ** power)
+ end.reduce(&:+)
+ [Integer(parsed_index[2]) - 1, col - 1]
+ end
+
+end
+
+
+class Spreadsheet
+ include SpreadSheetHelper
+
+ def initialize(sheet = '')
+ @sheet = parse_sheet sheet
+ end
+
+ def empty?
+ @sheet.empty?
+ end
+
+ def cell_at(cell_index)
+ index_vector = parse_index cell_index
+
+ if @sheet.length <= index_vector[0] ||
+ @sheet[index_vector[0]].length <= index_vector[1]
+ raise Error, "Cell '#{cell_index}' does not exist"
+ end
+ @sheet[index_vector[0]][index_vector[1]]
+ end
+
+ def [](cell_index)
+ evaluate_cell cell_at(cell_index)
+ end
+
+ def to_s
+ @sheet.map do |row|
+ row.map { |cell| evaluate_cell cell }.join("\t")
+ end.join("\n")
+ end
+
+ def evaluate_cell(cell)
+ return cell if cell[0] != '='
+ if is_number? cell[1..-1]
+ cell[1..-1]
+ elsif is_cell_reference? cell[1..-1]
+ self. [] cell[1..-1]
+ else
+ parse_formula cell[1..-1]
+ end
+ end
+
+ def evaluate_formula_parameters parameters
+ parameters.map do |item|
+ is_cell_reference?(item) ? (self. [] (item)).to_f : item.to_f
+ end
+ end
+
+
+ class Error < StandardError
+ end
+
+end