Mercurial > repos > other > adventofcode2023
comparison day5b.rb @ 10:25dda3397797
Partial attempt at day 5 part 2
Trying to intersect ranges to make new ranges.
Not working yet.
| author | IBBoard <dev@ibboard.co.uk> |
|---|---|
| date | Sat, 09 Dec 2023 15:46:29 +0000 |
| parents | |
| children | 7826431dbc4f |
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| 9:9ec95ff0d33d | 10:25dda3397797 |
|---|---|
| 1 #! /usr/bin/env ruby | |
| 2 | |
| 3 require 'set' | |
| 4 | |
| 5 if ARGV.length != 1 | |
| 6 abort("Incorrect arguments - needs input file") | |
| 7 elsif not File.exist? (ARGV[0]) | |
| 8 abort("File #{ARGV[0]} did not exist") | |
| 9 end | |
| 10 | |
| 11 file = ARGV[0] | |
| 12 | |
| 13 maps = Hash.new | |
| 14 | |
| 15 lines = File.open(file, "r").each_line(chomp: true) | |
| 16 | |
| 17 seeds = lines.first.split(":")[1].split(" ").map(&:to_i).each_slice(2).map {|v| v[0]..(v[0]+v[1])} | |
| 18 | |
| 19 puts "#{seeds}" | |
| 20 | |
| 21 RawMapping = Struct.new(:from, :to, :ranges) | |
| 22 MappingRange = Struct.new(:source_range, :offset) | |
| 23 | |
| 24 mappings = Array.new | |
| 25 mappings_array = [] | |
| 26 | |
| 27 lines.drop(1).reduce(mappings_array) do |mappings, val| | |
| 28 if m = /([a-z]+)-to-([a-z]+) map:/.match(val) then | |
| 29 mappings << RawMapping.new(m[1], m[2], []) | |
| 30 elsif val != "" then | |
| 31 dest_start, source_start, range_length = val.split(" ").map(&:to_i) | |
| 32 mappings[-1].ranges << MappingRange.new((source_start...(source_start + range_length)), dest_start - source_start) | |
| 33 end | |
| 34 mappings | |
| 35 end | |
| 36 | |
| 37 mappings = mappings_array.map {|mapping| [mapping.from, mapping]}.to_h | |
| 38 | |
| 39 def map_with_override(mappings, input) | |
| 40 puts "Mappings: #{mappings} - input: #{input}" | |
| 41 mappings.ranges.reduce(input) do |input_ranges, mapping| | |
| 42 puts "Input Ranges: #{input_ranges}; Mapping: #{mapping}" | |
| 43 input_ranges.flat_map do |input_range| | |
| 44 if mapping.source_range.cover?(input_range) | |
| 45 # Input is inside the mapped range | |
| 46 [(input_range.begin+mapping.offset)..(input_range.end+mapping.offset)] | |
| 47 elsif mapping.source_range.end < input_range.begin or input_range.end < mapping.source_range.begin | |
| 48 # Input is entirely outside the mapped range | |
| 49 [input_range] | |
| 50 elsif input_range.begin < mapping.source_range.begin | |
| 51 # Input straddles the start | |
| 52 [ | |
| 53 (input_range.begin+mapping.offset)...(mapping.source_range.begin+mapping.offset), | |
| 54 (mapping.source_range.begin+mapping.offset)..(input_range.end+mapping.offset) | |
| 55 ] | |
| 56 else | |
| 57 # Must straddle the end | |
| 58 [ | |
| 59 (input_range.begin+mapping.offset)...(mapping.source_range.end+mapping.offset), | |
| 60 (mapping.source_range.end+mapping.offset)..(input_range.end+mapping.offset) | |
| 61 ] | |
| 62 end | |
| 63 end | |
| 64 end | |
| 65 end | |
| 66 | |
| 67 steps = ["seed", "soil", "fertilizer", "water", "light", "temperature", "humidity"] | |
| 68 | |
| 69 # FIXME: Some negative values and 0s, and the final `min()` gets a nill value | |
| 70 puts steps.reduce(seeds) {|vals, map_name| map_with_override(mappings[map_name], vals)}.map{|v| v.min}.min() |