Finished day 5, part 1!

src/advent/day3.rb

@@ -98,7 +98,7 @@ class EngineLine
 
   def extract_engine_numbers
     digit_indexes = extract_digit_indexes @line
-    group_digit_indexes(digit_indexes).map &method(:create_engine_number)
+    group_digit_indexes(digit_indexes).hash &method(:create_engine_number)
   end
 
   def extract_gears
@@ -119,13 +119,13 @@ class Engine
   end
 
   def self.deserialize(ser)
-    els = ser.strip.split("\n").each_with_index.map { |line, idx| EngineLine.new idx, line}
+    els = ser.strip.split("\n").each_with_index.hash { |line, idx| EngineLine.new idx, line}
     return self.new els
   end
 
   def extract_engine_numbers
     @engine_lines
-      .map {|line| line.extract_engine_numbers}
+      .hash {|line| line.extract_engine_numbers}
       .flatten
   end
 
@@ -159,7 +159,7 @@ class Engine
 
   def is_adjacent(engine_number, gear)
     gear.get_neighbourhood
-        .map {|point| engine_number.is_located_on(point[:line_index], point[:column_index])}
+        .hash {|point| engine_number.is_located_on(point[:line_index], point[:column_index])}
         .any?
   end
 
@@ -170,15 +170,15 @@ class Engine
 
   def extract_gears
     @engine_lines
-      .map {|line| line.extract_gears}
+      .hash {|line| line.extract_gears}
       .flatten
   end
 
   def get_gear_ratios
     extract_gears
-      .map {|gear| get_adjacent_number_parts(gear)}
+      .hash {|gear| get_adjacent_number_parts(gear)}
       .filter {|adjacent_numbers| adjacent_numbers.length == 2}
-      .map {|adjacent_numbers| adjacent_numbers.map {|a| a.value} .reduce(1, :*)}
+      .hash {|adjacent_numbers| adjacent_numbers.hash {|a| a.value}.reduce(1, :*)}
   end
   attr_accessor :engine_lines
 end
@@ -190,6 +190,6 @@ input_content = File.open(input_file_name).read
 
 engine = Engine.deserialize input_content
 
-puts engine.extract_engine_numbers_that_touches_symbols.map {|e| e.value} .sum
+puts engine.extract_engine_numbers_that_touches_symbols.hash {|e| e.value}.sum
 puts engine.get_gear_ratios.sum