Hoo boy 2025 ruby day 5

ruby/2025/5/bin/problem

@@ -0,0 +1,6 @@
+#!/usr/bin/env ruby
+
+require "ingredient_management"
+im = IngredientManagement.for(STDIN.read.chomp)
+puts "Part 1: #{im.fresh_ingredient_ids.count}"
+puts "Part 2: #{im.all_fresh_ids_count}"

ruby/2025/5/lib/ingredient_management.rb

@@ -0,0 +1,56 @@
+class IngredientManagement
+  attr_reader :ranges, :ids
+  def initialize(ranges, ids)
+    @ranges = ranges
+    @ids = ids
+  end
+
+  def self.for(input)
+    ranges, ids = input.split("\n\n")
+    new(
+      ranges.split("\n").map{ |r| s, e = r.split("-").map(&:to_i); s..e },
+      ids.split("\n").map(&:to_i)
+    )
+  end
+
+  def fresh?(id)
+    ranges.any? { |range| range.include? id }
+  end
+
+  def fresh_ingredient_ids
+    ids.select { |id| fresh? id }
+  end
+
+  def all_fresh_ids
+    # this makes it OOM!
+    # return ranges.map(&:to_a).flatten.uniq
+    []
+  end
+
+  def all_fresh_ids_count
+    combine_ranges.map(&:size).sum
+  end
+
+  def combine_two_ranges(r1, r2)
+    return [r1, r2] if r2.begin > r1.end || r1.begin > r2.end
+
+    [([r1.begin, r2.begin].min)..([r1.end, r2.end].max)]
+  end
+
+  def combine_ranges(rs = ranges)
+    rs.sort_by!(&:begin)
+    index = 0
+    while index < rs.length - 1
+      c2r = combine_two_ranges(rs[index], rs[index + 1])
+      if c2r.length == 2 # did not combine
+        index += 1
+      else # combined
+        rs.delete_at(index)
+        rs.delete_at(index)
+        rs.insert(index, c2r[0])
+      end
+    end
+
+    rs
+  end
+end

ruby/2025/5/test/test_ingredient_management.rb

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+require "minitest/autorun"
+require "ingredient_management"
+
+class TestIngredientManagement < Minitest::Test
+  def database
+      <<-END
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32
+END
+    end
+  def test_fresh_ingredient_ids
+    im = IngredientManagement.for(database)
+    assert_equal([1,5,8,11,17,32], im.ids)
+    assert_equal([3..5, 10..14, 16..20, 12..18], im.ranges)
+    assert_equal([5, 11, 17], im.fresh_ingredient_ids)
+  end
+
+  def test_all_fresh_ids_count
+    im = IngredientManagement.for(database)
+    assert_equal(14, im.all_fresh_ids_count)
+  end
+
+  def test_combine_two_ranges
+    im = IngredientManagement.new([], [])
+    assert_equal([1..6, 9..12], im.combine_two_ranges(1..6, 9..12))
+    assert_equal([1..12], im.combine_two_ranges(1..9, 6..12))
+    assert_equal([1..12], im.combine_two_ranges(1..9, 1..12))
+  end
+
+  def test_combine_ranges
+    im = IngredientManagement.new([1..2, 3..4, 2..6, 9..12], [])
+    assert_equal([1..6, 9..12], im.combine_ranges)
+  end
+end