implement hw 1

2018/IvanKarpechanka/1/hw.rb

@@ -0,0 +1,34 @@
+def fact(n)
+  (1..n).inject(1, :*)
+end
+
+def binom(n, k)
+  fact(n) / (fact(k) * fact(n - k))
+end
+
+def pascals_row(row, first_el)
+  (0..row).map { |line| first_el * binom(row, line) }
+end
+
+puts 'Введите глубину дерева:'
+three_len = gets.chomp.to_i
+puts 'Введите базовый номер:'
+first_el = gets.chomp.to_i
+
+# to output a number with zeros in the beginning if its 
+# length is less than the length of the maximum element
+number_max_len = pascals_row(three_len, first_el).max.to_s.length
+console_len = 160
+gaps = (' ' * number_max_len)
+help_str = "\/#{gaps}\\#{gaps}" # Specifying a Tree Display Template
+(0..three_len).each do |i|
+  str = '' # to create an output line on the console of each line of the tree
+  pascals_row(i, first_el).each do |elem|
+  	str += elem.to_s.rjust(number_max_len, '0') + (gaps + '  ')
+  end
+  help1 = "#{' ' * three_len.to_s.length}"
+  puts  help1 + (help_str * i).chomp(gaps).center(console_len)
+
+  help2 = "#{i.to_s.rjust(three_len.to_s.length, '0')}"
+  puts  help2 + str.chomp(gaps + '  ').center(console_len, ',')
+end