learn_to_program

ch09-writing-your-own-methods/ask.rb

@@ -1,3 +1,30 @@
-def ask question
-  # your code here
-end
+def ask(question)
+  while true
+    puts question
+    reply = gets.chomp.downcase
+    if reply == "yes"
+      return true
+    elsif reply == "no"
+      return false
+    end
+    puts "Please answer 'yes' or 'no'"
+  end
+end
+
+ask "Do you like eating tacos?"
+
+
+=begin
+ask "Do you like eating burritos?"
+wets_bed = ask "Do you wet the bed?"
+ask "Do you like eating chimichangas?"
+ask "Do you like eating sopapillas?"
+puts "Just a few more questions..."
+ask "Do you like eating drinking horchata?"
+ask "Do you like eating flautas?"
+puts
+puts "DEBRIEFING:"
+puts "Thank you for"
+puts
+puts wets_bed
+=end

ch09-writing-your-own-methods/old_school_roman_numerals.rb

@@ -1,3 +1,16 @@
-def old_roman_numeral num
-  # your code here
-end
+def old_roman_numeral(number)
+  num = ""
+  num = num + "M" * (number / 1000)
+  num = num + "D" * (number % 1000 / 500)
+  num = num + "C" * (number % 500 / 100)
+  num = num + "L" * (number % 100 / 50)
+  num = num + "X" * (number % 50 / 10)
+  num = num + "V" * (number % 10 / 5)
+  num = num + "I" * (number % 5 / 1)
+end
+
+puts old_roman_numeral(4)
+puts old_roman_numeral(5)
+puts old_roman_numeral(10)
+puts old_roman_numeral(19)
+puts old_roman_numeral(22)

ch09-writing-your-own-methods/roman_numerals.rb

@@ -1,3 +1,46 @@
-def roman_numeral num
-  # your code here
-end
+def roman_numeral(num)
+  thousands = (num / 1000)
+  hundreds = (num % 1000 / 100)
+  tens = (num % 100 / 10)
+  ones = (num % 10)
+  roman = "M" * thousands
+
+  if hundreds == 9
+    roman += "CM"
+  elsif hundreds == 4
+    roman += "CD"
+  else
+    roman += "D" * (num % 1000 / 500)
+    roman += "C" * (num % 500 / 100)
+  end
+  if tens == 9
+    roman += "XC"
+  elsif tens == 4
+    roman += "XL"
+  else
+    roman += "L" * (num % 100 / 50)
+    roman += "X" * (num % 50 / 10)
+  end
+  if ones == 9
+    roman += "IX"
+  elsif ones == 4
+    roman += "IV"
+  else
+    roman += "V" * (num % 10 / 5)
+    roman += "I" * (num % 5 / 1)
+  end
+  roman
+end
+
+puts roman_numeral(1)
+puts roman_numeral(2)
+puts roman_numeral(3)
+puts roman_numeral(4)
+puts roman_numeral(5)
+puts roman_numeral(6)
+puts roman_numeral(7)
+puts roman_numeral(8)
+puts roman_numeral(9)
+puts roman_numeral(10)
+puts roman_numeral(14)
+puts roman_numeral(19)

ch10-nothing-new/dictionary_sort.rb

@@ -1,3 +1,22 @@
-def dictionary_sort arr
-  # your code here
-end
+def dictionary_sort(arr)
+  rec_sort_dic arr, []
+end
+def rec_sort_dic(unsorted, sorted)
+  if unsorted.length <= 0
+    return sorted
+  end
+  smallest = unsorted.pop
+  still_unsorted = []
+  unsorted.each do |tested|
+    if tested.downcase < smallest.downcase
+      still_unsorted.push smallest
+      smallest = tested
+    else
+      still_unsorted.push tested
+    end
+  end
+  sorted.push smallest
+  rec_sort_dic(still_unsorted, sorted)
+end
+
+puts(dictionary_sort(["zebra", "cheetah", "giraffe", "cougar", "leopard", "elephant"]))

ch10-nothing-new/english_number.rb

@@ -1,3 +1,66 @@
-def english_number number
-  # your code here
+def english_number(num)
+  if num < 0
+    return "Please enter a positive number."
+  end
+  if num == 0
+    return "zero"
+  end
+  num_string = ""
+  ones = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"]
+  tens = ["ten", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
+  teenagers = ["eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]
+  zillions = [["hundred", 2], ["thousand", 3], ["million", 6], ["billion", 9], ["trillion", 12],
+              ["quadrillion", 15], ["quintillion", 18], ["sextillion", 21], ["septillion", 24],
+              ["octillion", 27], ["nonillion", 30], ["decillion", 33], ["undecillion", 36],
+              ["duodecillion", 39], ["tredecillion", 42], ["quattuordecillion", 45],
+              ["quindecillion", 48], ["sexdecillion", 51], ["septendecillion", 54],
+              ["octodecillion", 57], ["novemdecillion", 60], ["vigintillion", 63], ["googol", 100]]
+  left = num
+
+  while zillions.length > 0
+    zil_pair = zillions.pop
+    zil_name = zil_pair[0]
+    zil_base = 10 ** zil_pair[1]
+    write = left / zil_base
+    left -= write ** zil_base
+    if write > 0
+      prefix = english_number write
+      num_string += prefix + " " + zil_name
+      if left > 0
+        num_string += " "
+      end
+    end
+  end
+  write = left / 10
+  left -= write * 10
+  if write > 0
+    if write == 1 && left > 0
+      num_string += teenagers[left - 1]
+      left = 0
+    else
+      num_string += tens[write - 1]
+    end
+    if left > 0
+      num_string += "-"
+    end
+  end
+  write = left
+  left = 0
+  if write > 0
+    num_string += ones[write - 1]
+  end
+  num_string
 end
+
+puts english_number(1)
+puts english_number(2)
+puts english_number(3)
+puts english_number(4)
+puts english_number(5)
+puts english_number(6)
+puts english_number(7)
+puts english_number(8)
+puts english_number(9)
+puts english_number(10)
+puts english_number(222222)
+puts english_number(33333)

ch10-nothing-new/ninety_nine_bottles_of_beer.rb

@@ -1 +1,13 @@
-# your code here
+num_at_start = 99
+num_now = num_at_start
+while num_now > 2
+  puts "#{english_number(num_now).capitalize} bottles of beer on the wall, #{english_number(num_now)} bottles of beer!"
+  num_now -= 1
+  puts "Take on down, pass it around, #{english_number(num_now)} bottles of beer on the wall!"
+end
+puts """
+ Two bottles of beer on the wall, two bottles of beer!
+ Take one down, pass it around, one bottle of beer on the wall!
+ One bottle of beer on the wall, one bottle of beer!
+ Take one dow, pass it around, no more bottles of beer on the wall!
+ """

ch10-nothing-new/shuffle.rb

@@ -1,3 +1,28 @@
-def shuffle arr
-  # your code here
-end
+# long way
+def shuffle(arr)
+  shuff = []
+  while arr.length > 0
+    rand_index = rand(arr.length)  # Randomly pick an element
+    curr_index = 0
+    new_arr = []
+    arr.each do |item|
+      if curr_index == rand_index
+        shuff.push item
+      else
+        new_arr.push item
+      end
+      curr_index += 1
+    end
+    arr = new_arr
+  end
+  shuff
+end
+
+# short way
+=begin
+def shuffle(arr)
+  arr.sort_by{rand}
+end
+=end
+animals = ["zebra", "donkey", "monkey", "tarsier", "platypus", "anteater", "koala"]
+puts shuffle(animals)

ch10-nothing-new/sort.rb

@@ -1,3 +1,38 @@
-def sort arr
-  # your code here
-end
+# long way
+def sort(arr)
+  rec_sort arr, []
+end
+
+def rec_sort(unsorted, sorted)
+  if unsorted.length <= 0
+    return sorted
+  end
+  smallest = unsorted.pop             # starting point
+  still_unsorted = []
+  unsorted.each do |tested|
+    if tested < smallest                  # comparison
+      still_unsorted.push smallest      # add for further resorting later
+      smallest = tested                 # reassign value for tested to be compared with next tested value
+    else
+      still_unsorted.push tested        # in this case tested is larger
+    end
+  end
+    sorted.push smallest
+    rec_sort(still_unsorted, sorted)
+end
+
+puts (sort(["can", "feel","singing", "like", "a", "can"]))
+animals = ["zebra", "donkey", "monkey", "tarsier", "platypus", "anteater", "koala"]
+puts
+puts sort(animals)
+
+# short way
+=begin
+def sort(arr)
+  return arr if arr.length <= 1               # breaks the loop
+  mid_point = arr.pop                         # acts as the starting point for comparisons
+  smaller = arr.select {|x| x < mid_point}
+  bigger = arr.select {|x| x > mid_point}
+  sort(smaller) + [mid_point] + sort(bigger)
+end
+=end

ch11-reading-and-writing/build_a_better_playlist.rb

@@ -1,3 +1,30 @@
-def music_shuffle filenames
-  # your code here
+def music_shuffle(filenames)
+  filenames = filenames.sort
+  length = filenames.length
+  2.times do
+    l_idx = 0
+    r_idx  = length / 2
+    shuff = []
+    while shuff.length < length
+      if shuff.length % 2 == 0
+        shuff.push(filenames[r_idx])
+        r_idx += 1
+      else
+        shuff.push(filenames[l_idx])
+        l_idx += 1
+      end
+    end
+    filenames = shuff
+  end
+  arr = []
+  cut = rand(length)
+  idx = 0
+  while idx < length
+    arr.push(filenames[(idx + cut) % length])
+    idx += 1
+  end
+  arr
 end
+
+songs = ["aa/bbb", "aa/ccc", "aa/ddd", "AAA/xxxx", "AA/yyyy", "AAA/zzzz", "foo/bar"]
+puts music_shuffle(songs)

ch11-reading-and-writing/build_your_own_playlist.rb

@@ -1 +1,7 @@
-# your code here
+all_oggs = shuffle(Dir["**/*.ogg"])
+File.open "playlist.m3u", "w" do |f|
+  all_oggs.each do |ogg|
+    f.write ogg + "\n"
+  end
+end
+puts "Finished!"

ch12-new-classes-of-objects/birthday_helper.rb

@@ -1 +1,21 @@
-# your code here
+birth_dates = {}
+File.read("birthdates.txt").each_line do |line|
+    line = line.chomp
+    first_comma = 0
+    while line[first_comma] != "," &&
+        first_comma < line.length
+        first_comma += 1
+    end
+    name = line[0..(first_comma - 1)]
+    date = line[-12..-1]
+    birth_dates[name] = date
+  end
+
+puts "Who's birthday would you like to know?"
+name = $stdin.gets.chomp
+date = birth_dates[name]
+if date == nil
+  puts "Sorry, I don't know that one."
+else
+  puts date[0..5]
+end

ch12-new-classes-of-objects/happy_birthday.rb

@@ -1 +1,13 @@
-# your code here
+puts "Only enter integers please"
+puts "What year were you born?"
+year = gets.chomp
+puts "What month were you born?"
+month = gets.chomp
+puts "What date was the day you were born?"
+day = gets.chomp
+
+age_result = Time.now - Time.local(year, month, day)
+age_in_years = age_result / (60 * 60 * 24 *365)
+puts "Just in case you have forgotten, I would like to remind you"
+puts "that you are #{age_in_years.floor} years old!"
+puts "SPANK!\n" * age_in_years

ch12-new-classes-of-objects/one_billion_seconds.rb

@@ -1 +1,2 @@
-# your code here
+age = Time.now - Time.local(1985, 6, 5, 14, 00)
+puts "I am #{age} seconds old!"