Solver of RubyKaigi 2019 Cookpad Daily Ruby Puzzles

result.txt

Example
2019-05-04 02:31:22 +0900
...........................
-----
def foo
  "Hello world" if%
       false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
!       false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
 !      false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
  !     false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
   !    false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
    !   false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
     !  false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
      ! false
end
puts foo
-----
.
-----
def foo
  "Hello world" if
       !false
end
puts foo
-----

-----
def foo
  "Hello world" if
       :false
end
puts foo
-----
..................
2019-05-04 02:44:11 +0900

Problem 1-1
2019-05-04 02:44:11 +0900
..........................................
-----
# Hint: Use Ruby 2.6
puts "#{"Goodbye" ..; "Hello"} world"
-----
.
-----
# Hint: Use Ruby 2.6
puts "#{"Goodbye" .. ;"Hello"} world"
-----
...............
2019-05-04 02:57:01 +0900

Problem 1-2
2019-05-04 02:57:01 +0900
.....
-----
puts$&.then {
  # Hint: &. is a safe
  # navigation operator
  "Hello world"
}
-----
.........................................................................
2019-05-04 03:14:12 +0900

Problem 1-3
2019-05-04 03:14:12 +0900
...................................................................................................
-----
include Math
# Hint: the most beautiful equation
Out, *,
     Count = $>,
             $<, E ** (2i * PI)
Out.puts("Hello world" *
         Count.abs.round)
-----
.........................................................
2019-05-04 03:48:55 +0900

Problem 2-1
2019-05-04 03:48:55 +0900
.....................................
-----
def say
  -> {
    "Hello world"
  }.
  # Hint: you should call the Proc.
  yield
end

puts say { "Goodbye world" }
-----
.
-----
def say
  -> {
    "Hello world"
  }
.  # Hint: you should call the Proc.
  yield
end

puts say { "Goodbye world" }
-----
.
-----
def say
  -> {
    "Hello world"
  }
 . # Hint: you should call the Proc.
  yield
end

puts say { "Goodbye world" }
-----
.
-----
def say
  -> {
    "Hello world"
  }
  .# Hint: you should call the Proc.
  yield
end

puts say { "Goodbye world" }
-----
...........................................................................
2019-05-04 04:14:21 +0900

Problem 2-2
2019-05-04 04:14:21 +0900
......................................................
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  #
 essentially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # 
essentially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # e
ssentially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # es
sentially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # ess
entially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # esse
ntially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essen
tially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essent
ially Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essenti
ally Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essentia
lly Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essential
ly Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essentiall
y Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essentially
 Fiber.
  yield "Hello world"
end

puts e.next
-----
.
-----
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essentially 
Fiber.
  yield "Hello world"
end

puts e.next
-----
.............................................
2019-05-04 04:39:07 +0900

Problem 2-3
2019-05-04 04:39:07 +0900
......................................................................
-----
$s = 0
def say(n = 0)
  $s = $s * 4 + n
end

i, j, k = 1, 2, 3

say if
say j
say k

# Hint: Binary representation.
$s != 35 or puts("Hello world")
-----
............................................................................
2019-05-04 05:11:20 +0900

Problem 3-1
2019-05-04 05:11:20 +0900
..............................................................................................................
-----
def say s="Hello", t:'world'
  "#{ s }#{ t } world"
end
# Hint: Arguments in Ruby are
# difficult.

puts say t:p
-----
..
2019-05-04 05:36:03 +0900

Problem 3-2
2019-05-04 05:36:03 +0900
..............
-----
def say s, t=#"Goodbye "
  # Hint: You can ignore a warning.
  s = "#{ s } #{ t }"
  t + "world"
end

puts say :Hello
-----
.......................................................................................................
2019-05-04 06:01:55 +0900

Problem 3-3
2019-05-04 06:01:55 +0900
...........................
-----
def say
  "Hello world" if%
    false && false
  # Hint: No hint!
end

puts say
-----
....................................................
2019-05-04 06:19:22 +0900

Extra 1
2019-05-04 06:19:22 +0900
...............................................................
-----
Hello = "Hello"

# Hint: Stop the recursion.
def Hello
  Hello%() +
    " world"
end

puts Hello()
-----
...................................
2019-05-04 06:41:46 +0900

Extra 2
2019-05-04 06:41:46 +0900
......
-----
s = "Dz"
# Hint: https://techlife.cookpad.com/entry/2018/12/25/110240
s == s.upcase or
  s == s.downcase or puts "Hello world"
-----
.......................................................................................................................
2019-05-04 07:09:22 +0900

Extra 3
2019-05-04 07:09:22 +0900
........
-----
def say\
  s = 'Small'
  t = 'world'
  puts "#{s} #{t}"
end

TracePoint.new(:line){|tp|
  tp.binding.local_variable_set(:s, 'Hello')
  tp.binding.local_variable_set(:t, 'Ruby')
  tp.disable
}.enable(target: method(:say))

say
-----
.....
-----
def say
  s %= 'Small'
  t = 'world'
  puts "#{s} #{t}"
end

TracePoint.new(:line){|tp|
  tp.binding.local_variable_set(:s, 'Hello')
  tp.binding.local_variable_set(:t, 'Ruby')
  tp.disable
}.enable(target: method(:say))

say
-----
....................................................................................................................................................................................................................
2019-05-04 07:59:10 +0900

solv.rb

CODES = {}

CODES["Example"] = <<'EOS'
def foo
  "Hello world" if
       false
end
puts foo
EOS

CODES["Problem 1-1"] = <<'EOS'
# Hint: Use Ruby 2.6
puts "#{"Goodbye" .. "Hello"} world"
EOS

CODES["Problem 1-2"] = <<'EOS'
puts&.then {
  # Hint: &. is a safe
  # navigation operator
  "Hello world"
}
EOS

CODES["Problem 1-3"] = <<'EOS'
include Math
# Hint: the most beautiful equation
Out, *,
     Count = $>,
             $<, E ** (2 * PI)
Out.puts("Hello world" *
         Count.abs.round)
EOS

CODES["Problem 2-1"] = <<'EOS'
def say
  -> {
    "Hello world"
  }
  # Hint: you should call the Proc.
  yield
end

puts say { "Goodbye world" }
EOS

CODES["Problem 2-2"] = <<'EOS'
e = Enumerator.new do |g|
  # Hint: Enumerator is
  # essentially Fiber.
  yield "Hello world"
end

puts e.next
EOS

CODES["Problem 2-3"] = <<'EOS'
$s = 0
def say(n = 0)
  $s = $s * 4 + n
end

i, j, k = 1, 2, 3

say i
say j
say k

# Hint: Binary representation.
$s != 35 or puts("Hello world")
EOS

CODES["Problem 3-1"] = <<'EOS'
def say s="Hello", t:'world'
  "#{ s }#{ t } world"
end
# Hint: Arguments in Ruby are
# difficult.

puts say :p
EOS

CODES["Problem 3-2"] = <<'EOS'
def say s, t="Goodbye "
  # Hint: You can ignore a warning.
  s = "#{ s } #{ t }"
  t + "world"
end

puts say :Hello
EOS

CODES["Problem 3-3"] = <<'EOS'
def say
  "Hello world" if
    false && false
  # Hint: No hint!
end

puts say
EOS

CODES["Extra 1"] = <<'EOS'
Hello = "Hello"

# Hint: Stop the recursion.
def Hello
  Hello() +
    " world"
end

puts Hello()
EOS

CODES["Extra 2"] = <<'EOS'
s = ""
# Hint: https://techlife.cookpad.com/entry/2018/12/25/110240
s == s.upcase or
  s == s.downcase or puts "Hello world"
EOS

CODES["Extra 3"] = <<'EOS'
def say
  s = 'Small'
  t = 'world'
  puts "#{s} #{t}"
end

TracePoint.new(:line){|tp|
  tp.binding.local_variable_set(:s, 'Hello')
  tp.binding.local_variable_set(:t, 'Ruby')
  tp.disable
}.enable(target: method(:say))

say
EOS


require 'timeout'

CHARS =
  ('0'..'9').to_a +
  ('a'..'z').to_a +
  ('A'..'Z').to_a +
  %w( ! ? # % & | + - * / ^ ' . , < > = ~ $ @ _ " : ` \\ ; ) +
  [' ', "\n", "Dz"]

CODES.each do |name, code|
  puts
  puts "#{name}"
  puts Time.now
  (0...code.length).each do |i|
    putc '.'
    CHARS.each do |char|
      code_inserted = code.clone.insert(i, char)
      File.open("code.rb", "w") { |f| f.puts(code_inserted) }
      begin
        Timeout.timeout(1) do
          result = `ruby code.rb 2>/dev/null`
          if result == "Hello world\n"
            puts
            puts '-----'
            puts code_inserted
            puts '-----'
          end
        end
      rescue Timeout::Error
      end
    end
  end
  puts
  puts Time.now
end