Ruby Academy Homework 01: rubeque, elementary level

homework_01.rb

# Solution to 'The Truth' on rubeque.com
# by mdyn
# http://rubeque.com/problems/the-truth

assert_equal true, true   

# Solution to 'Reverse' on rubeque.com
# by mdyn
# http://rubeque.com/problems/reverse

assert_equal 'nocab yknuhc'.reverse, 'chunky bacon'

# Solution to 'Hello World' on rubeque.com
# by mdyn
# http://rubeque.com/problems/hello-world

assert_equal 'HELLO WORLD', 'hello world'.upcase

# Solution to 'Maximum' on rubeque.com
# by mdyn
# http://rubeque.com/problems/maximum

def maximum(arr)
  arr.sort.last
end

assert_equal maximum([2, 42, 22, 02]), 42
assert_equal maximum([-2, 0, 33, 304, 2, -2]), 304
assert_equal maximum([1]), 1

# Solution to 'Nil Values' on rubeque.com
# by mdyn
# http://rubeque.com/problems/nil-values

[0, '', 'chunky_bacon'].each { |v| assert_equal v.nil?, false }

# Solution to 'Map' on rubeque.com
# by mdyn
# http://rubeque.com/problems/map

assert_equal [1, 4, 9, 16], (1..4).map { |element| element**2 }

# Solution to 'FizzBuzz' on rubeque.com
# by mdyn
# http://rubeque.com/problems/fizzbuzz

def fizzbuzz(x)
  return "FizzBuzz" if x % 15 == 0
return "Fizz" if x % 3 == 0
return "Buzz" if x % 5 == 0
x

end

assert_equal fizzbuzz(3), "Fizz"
assert_equal fizzbuzz(50), "Buzz"
assert_equal fizzbuzz(15), "FizzBuzz"
assert_equal fizzbuzz(5175), "FizzBuzz"

# Solution to 'The Curious Case of the Missing Method' on rubeque.com
# by mdyn
# http://rubeque.com/problems/the-curious-case-of-the-missing-method

assert_equal [1, 4, nil, 9, 16, nil].compact.inject(0) {|sum, number| sum + number}, 30

# Solution to 'Blackjack' on rubeque.com
# by mdyn
# http://rubeque.com/problems/blackjack

def twenty_one? *cards
  cards.reduce(:+) <= 21
end

assert_equal twenty_one?(3, 4, 5, 6, 3), true
assert_equal twenty_one?(3, 11, 10), false
assert_equal twenty_one?(10, 11), true

# Solution to 'The Curious Case of the Missing Method Part 2' on rubeque.com
# by mdyn
# http://rubeque.com/problems/the-curious-case-of-the-missing-method-part-2

assert_equal [1, 3, 7, 4, 9, 8].find(&:even?), 4

# Solution to 'Temperature Robot' on rubeque.com
# by mdyn
# http://rubeque.com/problems/temperature-robot

def temperature_bot(temp)
  # temperature bot is American but takes Celsius temperatures
  case temp
  when (18..21)
    "I like this temperature"
  else
    "This is uncomfortable for me"
  end
end

assert_equal temperature_bot(18), "I like this temperature"
assert_equal temperature_bot(21), "I like this temperature"
assert_equal temperature_bot(22), "This is uncomfortable for me"
assert_equal temperature_bot(-3), "This is uncomfortable for me"

# Solution to 'Injected and Rejected' on rubeque.com
# by mdyn
# http://rubeque.com/problems/injected-and-rejected

def sum_over_50(arr)
  arr.reject{|element| element <= 50}.reduce(0, :+)
end

assert_equal sum_over_50([29, 52, 77, 102]), 231
assert_equal sum_over_50([5, 11, 50]), 0
assert_equal sum_over_50([4, 8, 15, 16, 23, 42]), 0
assert_equal sum_over_50([300, 22, 1, 55, 42]), 355

# Solution to 'Home on the Range' on rubeque.com
# by mdyn
# http://rubeque.com/problems/home-on-the-range

assert_equal (1..100).to_a[11..94].reduce(:+), 4494

# Solution to 'There's No Way This Works' on rubeque.com
# by mdyn
# http://rubeque.com/problems/there-quo-s-no-way-this-works

@name = "Dave"
str = "My mind is going #@name"

assert_equal (str == "My mind is going Dave"), true

# Solution to 'Array Item Removal' on rubeque.com
# by mdyn
# http://rubeque.com/problems/array-item-removal

assert_equal ([:r, :u, :b, :e, :q, :u, :e] [2..4].rotate.reverse[0..1]), [:b, :q]

# Solution to '&& Versus And' on rubeque.com
# by mdyn
# http://rubeque.com/problems/-and--and--versus-and

roses = "blue" && "red"
violets = "blue" and "red"

assert_equal roses, "red"
assert_equal violets, 'blue'

# Solution to 'Subtracting Out The Sugar' on rubeque.com
# by mdyn
# http://rubeque.com/problems/subtracting-out-the-sugar

assert_equal 2.+(2), 2 + 2
assert_equal 40.+(2), 42

# Solution to 'There's No Way This Works Version 2' on rubeque.com
# by mdyn
# http://rubeque.com/problems/there-quo-s-no-way-this-works-version-2

str = "Hello" "World"

assert_equal str, "HelloWorld"

# Solution to 'Brackets and Searches' on rubeque.com
# by mdyn
# http://rubeque.com/problems/brackets-and-searches

assert_equal "hello world"['e'], "e"
assert_equal "what"['e'],        nil
assert_equal "rubeque"['e'],     "e"
assert_equal "E"['e'],           nil

# Solution to 'Or Equal' on rubeque.com
# by mdyn
# http://rubeque.com/problems/or-equal

b = 8
c = false

a ||= "rubeque"
b ||= "rubeque"
c ||= "rubeque"

assert_equal a, "rubeque"
assert_equal b, 8
assert_equal c, "rubeque"

# Solution to 'Alternate Array Notation' on rubeque.com
# by mdyn
# http://rubeque.com/problems/alternate-array-notation

assert_equal %w(hello world), ["hello", "world"]
assert_equal %w{1 2 3 4}, ["1", "2", "3", "4"]
assert_equal %w?remembrance of things past?, ["remembrance", "of", "things", "past"]

# Solution to 'Set Intersection' on rubeque.com
# by mdyn
# http://rubeque.com/problems/set-intersection

assert_equal ([ 1, 1, 3, 5 ] & [ 1, 2, 3 ]), [ 1, 3 ]

# Solution to 'Getters and Setters' on rubeque.com
# by mdyn
# http://rubeque.com/problems/getters-and-setters

class Character
  attr_accessor :name, :quote
end

thorin = Character.new
thorin.name = "Thorin Oakenshield"
thorin.quote = "Some courage and some wisdom, blended in measure. If more of us valued food 
  and cheer and song above hoarded gold, it would be a merrier world"
  
stephen = Character.new
stephen.name = "Stephen Dedalus"
  
assert_equal thorin.name, "Thorin Oakenshield" 
assert_equal stephen.name, "Stephen Dedalus"

# Solution to 'Queue Continuum' on rubeque.com
# by mdyn
# http://rubeque.com/problems/queue-continuum

class Queue
  def initialize(arr)
  @arr = arr
end
def pop(*idx)
  @arr.shift *idx
end
def push(elem)
  @arr.push(*elem) == @arr
end
def to_a
  @arr
end
end

queue = Queue.new([5, 6, 7, 8])

assert_equal queue.pop, 5
assert_equal queue.pop, 6
assert_equal queue.push([4, 2]), true
assert_equal queue.pop(2), [7, 8]
assert_equal queue.to_a, [4, 2]

# Solution to 'Ternary Operator' on rubeque.com
# by mdyn
# http://rubeque.com/problems/ternary-operator

a = "Miles O'Brien"
b = "Barack Obama"

assert_equal ((a =~ /[ ]\w'/) ? "Irish" : "Not Irish"), "Irish"
assert_equal ((b =~ /[ ]\w'/) ? "Irish" : "Not Irish"), "Not Irish"

# Solution to 'The Limits of Probability' on rubeque.com
# by mdyn
# http://rubeque.com/problems/the-limits-of-probability

random_values = (0..1000000).inject(0.0) do |sum, _| 
  sum += rand(14) + rand(14)
end

assert_equal (random_values/1000000.0).round, 13

# Solution to 'Caution Case' on rubeque.com
# by mdyn
# http://rubeque.com/problems/caution-case

def caution_case(obj)
  case obj
  when obj
    true
  else
    false
  end
end

assert_equal caution_case( 1 ), true
assert_equal caution_case( [1, 2] ), true
assert_equal caution_case( {1=>2} ), true
assert_equal caution_case( (1..2) ), false

# Solution to 'The Curious Case of the Missing Method Part 3' on rubeque.com
# by mdyn
# http://rubeque.com/problems/the-curious-case-of-the-missing-method-part-3

a1 = [1, 2, 3]
a2 = [2, 3, 4]
b1 = ["durham", "bartow", "zwolle"]
b2 = ["nc", "fl", "nl"]

assert_equal a1.zip(a2), [[1, 2], [2, 3], [3, 4]]
assert_equal [10, 11, 12].zip(a1, a2), [[10, 1, 2], [11, 2, 3], [12, 3, 4]]
assert_equal b1.zip(b2), [["durham", "nc"], ["bartow", "fl"], ["zwolle", "nl"]]

# Solution to 'Baby Got Stacks' on rubeque.com
# by mdyn
# http://rubeque.com/problems/baby-got-stacks

class Stack
  def initialize(stack)
    @stack = stack
end

def pop(*idx)
    result = @stack.pop(*idx)
    return result.reverse if result.is_a? Array
    result
end

def push(items)
    @stack.push(*items) == @stack
end

def to_a
    @stack
end

def to_a
  @stack
end
end

stack = Stack.new([5, 6, 7, 8])

assert_equal stack.pop, 8
assert_equal stack.pop, 7
assert_equal stack.push([4, 2]), true
assert_equal stack.pop(3), [2, 4, 6]
assert_equal stack.to_a, [5]

# Solution to 'No Limit' on rubeque.com
# by mdyn
# http://rubeque.com/problems/no-limit

assert_equal ["1", "2", "3"], "1,2,3".split(',', -1)
assert_equal ["", "", "1", "2", "3"], ",,1,2,3".split(',', -1)
assert_equal ["1", "2", "3", "", ""], "1,2,3,,".split(',', -1)

# Solution to 'Defined? Or not?' on rubeque.com
# by mdyn
# http://rubeque.com/problems/defined-ques--or-not-ques-

if false
  w = :whatever
end

assert_equal defined?(w) != nil, true

# Solution to 'The Curious Case of the Missing Method Part 4' on rubeque.com
# by mdyn
# http://rubeque.com/problems/the-curious-case-of-the-missing-method-part-4

class A
end

class B < A
end

assert_equal B.ancestors[1], A

# Solution to 'Default Encoding' on rubeque.com
# by mdyn
# http://rubeque.com/problems/default-encoding

assert_equal "".encoding, Encoding::US_ASCII
assert_equal "ascii compatible string".encoding, Encoding::US_ASCII

# Solution to 'The Curious Case of the Missing Method Part 5' on rubeque.com
# by mdyn
# http://rubeque.com/problems/the-curious-case-of-the-missing-method-part-5

trilogy = [["Sympathy for Mr Vengeance", "Ryu", "Cha Yeong-mi"], ["Oldboy", "Oh Dae-su", "Kang Hye-jeong"], 
  ["Sympathy for Lady Vengeance", "Lee Geum-ja"]]
  
assert_equal trilogy.assoc("Sympathy for Lady Vengeance"), ["Sympathy for Lady Vengeance", "Lee Geum-ja"]
assert_equal trilogy.rassoc("Ryu"), ["Sympathy for Mr Vengeance", "Ryu", "Cha Yeong-mi"]
assert_equal trilogy.rassoc("Lee Geum-ja"), ["Sympathy for Lady Vengeance", "Lee Geum-ja"]

# Solution to 'Phanaeng Curry' on rubeque.com
# by mdyn
# http://rubeque.com/problems/phanaeng-curry

exponential = -> x, y { y ** x }
squared = exponential.curry[2]

assert_equal squared.(3) == 9, true

# Solution to 'Shotgun Assignment' on rubeque.com
# by mdyn
# http://rubeque.com/problems/shotgun-assignment

a, b, c = ["eat", "chunky", "bacon"]

assert_equal a, "eat"
assert_equal b, "chunky"
assert_equal c, "bacon"

# Solution to 'Bigger element' on rubeque.com
# by mdyn
# http://rubeque.com/problems/bigger-element

def first_even(items)
  items.detect(&:even?)
end