1 files changed, 43 insertions, 0 deletions
diff --git a/digits.rb b/digits.rb
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index 0000000..addc51e
--- /dev/null
+++ b/digits.rb
@@ -0,0 +1,43 @@
+#!/usr/bin/env ruby
+
+require 'optimist'
+
+opts = Optimist::options do
+  version "digits 0.2 (c) 2023 Nat Lasseter"
+  banner <<-EOS
+Digits gives valid combinations of digits 1-9 that sum to the given total
+
+Usage:
+  digits [opts]
+
+where [opts] are:
+EOS
+
+  opt :number, "The number of digits", type: :integer
+  opt :target, "The target sum", type: :integer
+  opt :exclude, "Exclude a digit", type: :integer, multi: true
+  opt :include, "Include a digit", type: :integer, multi: true
+
+  educate_on_error
+end
+
+digits = [1,2,3,4,5,6,7,8,9]
+opts[:exclude].each { |i| digits.delete(i) }
+
+def puts_group(digits, mandatory, number, target = nil)
+  if target.nil?
+    puts digits.combination(number).select { |a| (mandatory - a).empty? }.sort { |a, b| a.sum <=> b.sum }.map { |a| "#{a.join} = #{a.sum}" }
+  else
+    puts digits.combination(number).select { |a| a.sum == target }.select { |a| (mandatory - a).empty? }.map { |a| "#{a.join} = #{target}" }
+  end
+end
+
+if opts[:number_given]
+  puts "== #{opts[:number]} =="
+  puts_group(digits, opts[:include], opts[:number], opts[:target])
+else
+  (2..8).each do |n|
+    puts "== #{n} =="
+    puts_group(digits, opts[:include], n, opts[:target])
+  end
+end