day4.cr

@@ -1,6 +1,20 @@
-require "./passports.cr"
 INPUT = File.read("day4.txt")
 
+def parse_passport(string)
+  new_hash = {} of String => String
+  string.split(" ").each do |field|
+    k,v = field.split(":")
+    new_hash[k] = v
+  end
+  new_hash
+end
+
+def parse_passports(lines)
+  lines.split(/\n\n/).map do |s|
+    parse_passport(s.chomp.gsub(/\n/, " "))
+  end
+end
+
 def part1
   input = INPUT.clone
   passports = parse_passports(input)
@@ -12,16 +26,35 @@ def part1
   puts total
 end
 
+def validate_range(range)
+  ->(s : String) { s.to_i32?.try { |i| range.includes? i } }
+end
+
+def validate_regex(regex)
+  ->(s : String) { s.matches?(regex) }
+end
+
 def part2
   input = INPUT.clone
   passports = parse_passports(input)
-  valid_passports = [] of Passport
+  validators = {
-  passports.each do |p|
+    "byr" => validate_range(1920..2002),
-    if vp = Passport.from_hash?(p)
+    "iyr" => validate_range(2010..2020),
-      valid_passports << vp 
+    "eyr" => validate_range(2020..2030),
+    "hgt" => ->(s : String) {
+      return false unless s.match(/^(\d+)(cm|in)$/)
+      validate_range($~[2] == "cm" ? (150..193) : (59..76)).call($~[1])
+    },
+    "hcl" => validate_regex(/^#[0-9a-f]{6}$/),
+    "ecl" => ->(s : String) { "amb blu brn gry grn hzl oth".split(" ").includes? s },
+    "pid" => ->(s : String) { s =~ /^[0-9]{9}$/ },
+  }
+  total = passports.count do |passport|
+    validators.all? do |k, v|
+      passport[k]?.try { |s| v.call(s) }
     end
   end
-  puts valid_passports.size
+  puts total
 end
 
 part1

day5.cr

@@ -1,55 +0,0 @@
-INPUT = File.read("day5.txt").lines.map(&.chomp) 
-
-def partition(choices, list)
-  b = 0
-  e = list.size
-  choices.chars.each do |c|
-    b = (b+e)//2 if c == 'B' || c == 'R'
-    e = (b+e)//2 if c == 'F' || c == 'L'
-  end
-
-  return {b,e}
-end
-
-def get_id(str)
-  col = str[0..6]
-  row = str[7..]
-  {partition(col, (0..127).to_a)[0], partition(row, (0..7).to_a)[0]}
-end
-
-def id(t)
-  r, c = t
-  r * 8 + c
-end
-
-def part1
-  input = INPUT.clone
-  max = input.max_of do |line|
-    r, c = get_id(line)
-    r * 8 + c
-  end
-  puts max
-end
-
-def part2
-  input = INPUT.clone
-  seen = Set(Int32).new
-  max = input.each do |line|
-    seen << id(get_id(line))
-  end
-  candidates = [] of Int32
-  128.times do |r|
-    next if r == 0 || r == 127
-    8.times do |c|
-      next if seen.includes? id({r, c})
-      candidates << id({r,c})
-    end
-  end
-  candidates = candidates.select do |i|
-    seen.includes?(i-1) && seen.includes?(i+1)
-  end
-  puts candidates[0]
-end
-
-part1
-part2

graph.cr

@@ -1,48 +0,0 @@
-class Graph(A)
-  def initialize
-    @edges = {} of A => Set({A, Int32})
-  end
-
-  def add_edge(f, t, c = 1)
-    @edges[f] ||= Set({A, Int32}).new
-    @edges[f] << {t, c}
-  end
-
-  def add_biedge(f, t, c = 1)
-    add_edge(f, t, c)
-    add_edge(t, f, c)
-  end
-
-  def find_path(f, t)
-    visited = Set(A).new
-    candidates = Set { f }
-    distances = {f => 0}
-    prev = {} of A => A
-
-    while !candidates.empty?
-      candidate = candidates.min_by { |c| distances[c] }
-      break if candidate == t
-      visited << candidate
-      candidates.delete candidate
-      dist = distances[candidate]
-
-      @edges.fetch(candidate, Set({A, Int32}).new).each do |e|
-        node, cost = e
-        new_dist = dist + cost
-        candidates << node unless visited.includes? node
-        next if (old_dist = distances[node]?) && old_dist < new_dist
-        distances[node] = new_dist 
-        prev[node] = candidate
-      end
-    end
-
-    backtrack = t
-    path = [t] of A
-    while backtrack != f
-      return nil unless prev_bt = prev[backtrack]?
-      path << prev_bt
-      backtrack = prev_bt
-    end
-    {path.reverse!, distances[t]}
-  end
-end

passports.cr

@@ -1,86 +0,0 @@
-def parse_passport(string)
-  new_hash = {} of String => String
-  string.split(" ").each do |field|
-    k,v = field.split(":")
-    new_hash[k] = v
-  end
-  new_hash
-end
-
-def parse_passports(lines)
-  lines.split(/\n\n/).map do |s|
-    parse_passport(s.chomp.gsub(/\n/, " "))
-  end
-end
-
-class Validator(T, R)
-  def initialize(@proc : Proc(T, R?))
-  end
-
-  def >>(other)
-    Validator.new(->(i : T) { @proc.call(i).try { |j| other.@proc.call(j) } })
-  end
-
-  def then(&block : R -> S?) forall S
-    Validator(T, S).new(->(i : T) { @proc.call(i).try { |j| block.call(j) } })
-  end
-
-  def run(input)
-    @proc.call(input)
-  end
-end
-
-class Hash(K,V)
-  def validate(k, vl)
-    self[k]?.try { |v| vl.run(v) }
-  end
-end
-
-def range(range) : Validator(Int32, Int32)
-  Validator.new ->(i : Int32) { (range.includes? i) ? i : nil }
-end
-
-def int : Validator(String, Int32)
-  Validator.new ->(s : String) { s.to_i32? }
-end
-
-def regex(regex) : Validator(String, Regex::MatchData)
-  Validator(String, Regex::MatchData).new ->(s : String) { s.match(regex) }
-end
-
-def oneof(strs : Array(A)) : Validator(A, A) forall A
-  Validator(String, String).new ->(s : String) { (strs.includes? s) ? s : nil }
-end
-
-def length(len) : Validator(String, String)
-  Validator(String, String).new ->(s : String) { (s.size == len) ? s : nil }
-end
-
-def year(rng) : Validator(String, Int32)
-  length(4) >> int >> range(rng)
-end
-
-def unit_range(map) : Validator(String, {String, Int32})
-  regex(/(\d+)([a-zA-Z]+)/).then do |md|
-    map[md[2]]?.try { |r| (int >> range(r)).run(md[1]).try { |i| {md[2], i} } }
-  end
-end
-
-class Passport
-  def initialize(
-    @byr : Int32, @iyr : Int32,
-    @eyr : Int32, @hgt : {String, Int32},
-    @hcl : String, @ecl : String, @pid : Int32)
-  end
-
-  def self.from_hash?(hash)
-    return nil unless byr = hash.validate("byr", year(1920..2002))
-    return nil unless iyr = hash.validate("iyr", year(2010..2020))
-    return nil unless eyr = hash.validate("eyr", year(2020..2030))
-    return nil unless hgt = hash.validate("hgt", unit_range({"cm" => (150..193), "in" => (59..76)}))
-    return nil unless hcl = hash.validate("hcl", regex(/^#([0-9a-f]{6})$/).then { |d| d[1] })
-    return nil unless ecl = hash.validate("ecl", oneof(["amb", "blu", "brn", "gry", "grn", "hzl", "oth"]))
-    return nil unless pid = hash.validate("pid", length(9) >> int)
-    Passport.new(byr, iyr, eyr, hgt, hcl, ecl, pid)
-  end
-end