Efraim's solution

00_hello/hello.rb

@@ -0,0 +1,7 @@
+def hello
+  "Hello!"
+end
+
+def greet(name)
+  "Hello, #{name}!"
+end

01_temperature/temperature.rb

@@ -0,0 +1,7 @@
+def ftoc(degrees)
+  (degrees - 32).to_f * 5.0 / 9.0
+end
+
+def ctof(d)
+  d * 9.0 / 5.0 + 32.0
+end

02_calculator/calculator.rb

@@ -0,0 +1,27 @@
+def add(x, y)
+  x + y
+end
+
+def subtract(x, y)
+  x - y
+end
+
+def sum(nums)
+  nums.reduce(0){ |total, n| total + n }
+end
+
+def multiply(*nums)
+  nums.reduce(1){ |total, n| total * n }
+end
+
+def power(x, y)
+  x ** y
+end
+
+def factorial(x)
+  if x <= 1
+    1
+  else
+    x * factorial(x - 1)
+  end
+end

02_calculator/calculator_spec.rb

@@ -79,21 +79,41 @@
 
 describe "#multiply" do
 
-  it "multiplies two numbers"
+  it "multiplies two numbers" do
+    expect(multiply(3,3)).to eq(9)
+  end
+
+  it "multiplies several numbers" do
+    expect(multiply(3, 4, 5)).to eq(60)
+  end
 
-  it "multiplies several numbers"
-
 end
 
 describe "#power" do
-  it "raises one number to the power of another number"
+  it "raises one number to the power of another number" do
+    expect(power(2, 3)).to eq(8)
+  end
 end
 
 # http://en.wikipedia.org/wiki/Factorial
 describe "#factorial" do
-  it "computes the factorial of 0"
-  it "computes the factorial of 1"
-  it "computes the factorial of 2"
-  it "computes the factorial of 5"
-  it "computes the factorial of 10"
+  it "computes the factorial of 0" do
+    expect(factorial(0)).to eq(1)
+  end
+
+  it "computes the factorial of 1" do
+    expect(factorial(1)).to eq(1)
+  end
+
+  it "computes the factorial of 2" do
+    expect(factorial(2)).to eq(2)
+  end
+
+  it "computes the factorial of 5" do
+    expect(factorial(5)).to eq(120)
+  end
+
+  it "computes the factorial of 10" do
+    expect(factorial(10)).to eq(3628800)
+  end
 end

03_simon_says/simon_says.rb

@@ -0,0 +1,40 @@
+def echo(s)
+  s
+end
+
+def shout(s)
+  s.upcase
+end
+
+def repeat(s, times=2)
+  if times <= 1
+    s
+  else
+    s + " " + repeat(s, times - 1)
+  end
+end
+
+def start_of_word(s, length)
+  s[0...length]
+end
+
+def first_word(s)
+  s.split(" ")[0]
+end
+
+def titleize(s)
+  littlewords = ["the", "and", "over"]
+  split = s.split(" ")
+  capwords = split.each_with_index.map do |word, i|
+    if i == 0 && split[0] == word
+      word.capitalize
+    elsif littlewords.include?(word)
+      word
+    else
+      word.capitalize
+    end
+  end
+  capwords.join(" ")
+end
+
+titleize("the bridge over the river kwai")

04_pig_latin/pig_latin.rb

@@ -0,0 +1,24 @@
+def translate(s)
+  vowels = "aeiou".split("")
+  split = s.split(" ")
+  split.reduce([]) do |acc, word|
+    # begins with vowel
+    if vowels.include?(word[0].downcase)
+      word = word + "ay"
+      # with 3 consonants
+    elsif word[0..2].split("").all?{ |char| not(vowels.include?(char)) } ||
+          (not(vowels.include?(word[0])) && word[1..2] == "qu")
+      word = word[3..-1] + word[0..2] + "ay"
+      # with 2 consonants
+    elsif word[0..1].split("").all?{ |char| not(vowels.include?(char)) } ||
+          word[0..1].downcase == "qu"
+      word = word[2..-1] + word[0..1] + "ay"
+      # with 1 consonant
+    else
+      word = word[1..-1] + word[0] + "ay"
+    end
+    acc.push(word)
+  end.join(" ")
+end
+
+translate("the quick brown fox")

05_silly_blocks/silly_blocks.rb

@@ -0,0 +1,13 @@
+def reverser
+  yield.split(" ").map(&:reverse).join(" ")
+end
+
+def adder(n=1)
+  yield + n
+end
+
+def repeater(times=1)
+  times.times do
+    yield
+  end
+end

06_performance_monitor/performance_monitor.rb

@@ -0,0 +1,11 @@
+require "time"
+
+def measure(times=1)
+  acc = []
+  times.times do
+    start = Time.now
+    yield
+    acc.push(Time.now - start)
+  end
+  acc.reduce(&:+).to_f / times.to_f
+end

07_hello_friend/friend.rb

@@ -0,0 +1,9 @@
+class Friend
+  def greeting(name=nil)
+    if name
+      "Hello, #{name}!"
+    else
+      "Hello!"
+    end
+  end
+end

08_book_titles/book.rb

@@ -0,0 +1,24 @@
+class Book
+
+  attr_reader :title, :app_state
+
+  def initialize
+    @app_state = {
+      exceptions: "the a an and in of".split(" ")
+    }
+    @title = nil
+  end
+
+  def title=(s)
+    @title = s.split(" ").each_with_index.map do |word, i|
+      if i == 0
+        word.capitalize
+      elsif app_state[:exceptions].include?(word)
+        word
+      else
+        word.capitalize
+      end
+    end.join(" ")
+  end
+
+end

09_timer/timer.rb

@@ -0,0 +1,22 @@
+class Timer
+  attr_accessor :seconds
+
+  def initialize
+    @seconds = 0
+  end
+
+  def pre_zero(int)
+    if int.to_s.length == 1
+      "0#{int}"
+    else
+      int.to_s
+    end
+  end
+
+  def time_string
+    seconds_left = seconds % 60
+    minutes_left = (seconds/60) % 60
+    hour = (seconds/60) / 60
+    "#{pre_zero(hour)}:#{pre_zero(minutes_left)}:#{pre_zero(seconds_left)}"
+  end
+end

10_temperature_object/temperature.rb

@@ -0,0 +1,89 @@
+def ftoc(degrees)
+  (degrees - 32).to_f * 5.0 / 9.0
+end
+
+def ctof(d)
+  d * 9.0 / 5.0 + 32.0
+end
+
+# ----------------------------------------------------------------------
+# Temperature
+# ----------------------------------------------------------------------
+
+class Temperature
+
+  attr_accessor :degrees
+
+  def initialize(options = {})
+    @degrees = options
+  end
+
+  def self.from_celsius(d)
+    Temperature.new({c: d})
+  end
+
+  def self.from_fahrenheit(d)
+    Temperature.new({f: d})
+  end
+
+  def in_fahrenheit
+    if degrees[:f]
+      degrees[:f]
+    else
+      ctof(degrees[:c])
+    end
+  end
+
+  def in_celsius
+    if degrees[:f]
+      ftoc(degrees[:f])
+    else
+      degrees[:c]
+    end
+  end
+
+end
+
+# ----------------------------------------------------------------------
+# Celsius
+# ----------------------------------------------------------------------
+
+class Celsius < Temperature
+
+  attr_accessor :degree
+
+  def initialize(d)
+    @degree = d
+  end
+
+  def in_celsius
+    degree
+  end
+
+  def in_fahrenheit
+    ctof(degree)
+  end
+
+end
+
+# ----------------------------------------------------------------------
+# Fahrenheit
+# ----------------------------------------------------------------------
+
+class Fahrenheit < Temperature
+
+  attr_accessor :degree
+
+  def initialize(d)
+    @degree = d
+  end
+
+  def in_fahrenheit
+    degree
+  end
+
+  def in_celsius
+    ftoc(degree)
+  end
+
+end

11_dictionary/dictionary.rb

@@ -0,0 +1,41 @@
+class Dictionary
+
+  attr_accessor :entries
+
+  def initialize
+    @entries = {}
+  end
+
+  def add(keyvals)
+    if keyvals.is_a?(Hash)
+      @entries = entries.merge(keyvals)
+    else
+      @entries = entries.merge({keyvals => nil})
+    end
+  end
+
+  def keywords
+    entries.keys.sort
+  end
+
+  def include?(k)
+    entries.include?(k)
+  end
+
+  def find(s)
+    entries.select{ |k, v| k.include?(s) }
+  end
+
+  def printable
+    entries.sort.reduce("") do |acc, kv|
+      k, v = kv
+      s = %Q{[#{k}] "#{v}"}
+      if acc.empty?
+        s
+      else
+        acc + "\n" + s
+      end
+    end
+  end
+
+end