updated ask.rb

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

@@ -1,3 +1,25 @@
 def ask question
-  # your code here
-end
+  while true
+    puts question
+    reply = gets.chomp.downcase
+
+    return true if reply =='yes'
+    return false if reply == 'no'
+    puts 'Please answer "yes" or "no".'
+  end
+end
+
+
+puts 'Hello, and thank you for...'
+puts
+
+ask 'Do you like eating tacos?'
+ask 'Do you like eating burritos?'
+wets_bed = ask 'Do you wet the bed?'
+ask 'Do you like eating chimichangas?'
+
+puts
+puts 'DEBRIEFING'
+puts 'Thank you for...'
+puts
+puts wets_bed

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

@@ -1,3 +1,17 @@
 def old_roman_numeral num
   # your code here
-end
+
+roman = ''
+
+roman << 'M'*(num /1000)
+roman << 'D'*(num %1000 /500)
+roman << 'C'*(num %500 /100)
+roman << 'L'*(num %100 /50)
+roman << 'X'*(num %50 /10)
+roman << 'V'*(num %10 /5)
+roman << 'I'*(num %5 /1)
+
+roman
+end
+
+puts old_roman_numeral(1991)

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

@@ -1,3 +1,41 @@
 def roman_numeral num
-  # your code here
-end
+
+thousand = num/1000
+hundred = num %1000 /100
+ten = num%100 / 10
+ones = num % 10 / 1
+
+roman = 'M' * thousand
+  if hundred ==9
+    roman << 'CM'
+  elsif hundred == 4
+    roman << 'CD'
+  else
+    roman << 'D' * (num %1000 /500)
+    roman << 'C' * (num %500 /100)
+  end
+
+  if ten == 9
+    roman << 'XC'
+  elsif ten == 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(1984)

ch10-nothing-new/dictionary_sort.rb

@@ -1,3 +1,26 @@
 def dictionary_sort arr
-  # your code here
-end
+  rec_dict_sort arr,[]
+end
+
+def rec_dict_sort unsorted_array, sorted_array
+  if unsorted_array.length <=0
+    return sorted_array
+  end
+
+  smallest = unsorted_array.pop
+  still_unsorted = []
+
+  unsorted_array.each do |word|
+    if word.downcase < smallest.downcase
+      still_unsorted.push smallest
+      smallest = word
+    else
+      still_unsorted.push word
+    end
+  end
+
+  sorted_array.push smallest
+  rec_dict_sort still_unsorted, sorted_array
+end
+
+puts(dictionary_sort(['can','feel','like','singing','A','can']))

ch10-nothing-new/english_number.rb

@@ -1,3 +1,64 @@
 def english_number number
-  # your code here
+  if number <0
+    return 'Please enter a number that isn\'t negative'
+  end
+  if number ==0
+    return 'zero'
+  end
+
+  num_string =""
+
+  ones_place = ['one','two','three','four','five','six','seven','eight','nine']
+  tens_place = ['ten','twenty','thirty','fourty','fifty','sixty','seventy','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',39],
+['duodecillion',39],['tredecillion',42],['quattuordecillion',45],['quindecillion',48],
+['sexdecillion',51],['septendectillion',54],['octodecillion',57],['novemdecillion',60],
+['vigintillion',63],['googol',100]]
+
+#'left' is how much left of the number we still have t write
+#'write' is the part we are writing out right now
+
+left = number
+while zillions.length >0
+  zil_pair = zillions.pop
+  zil_name = zil_pair[0]
+  zil_base = 10 ** zil_pair[1]
+  write = left /zil_base
+  left = left - write*zil_base
+
+if write > 0
+  prefix =english_number write
+  num_string = num_string + prefix + ' ' + zil_name
+  if left > 0
+    num_string = num_string +' '
+  end
 end
+
+write = left/10
+left = left -write*10
+
+if write >0
+  if write ((write ==1) and (left >0))
+    num_string =num_string + teenagers[left-1]
+    left =0
+  else
+    num_string = num_string + tens_place[write-1]
+  end
+end
+
+write=left
+left=0
+if write >0
+  num_string = num_string+ones_place[write-1]
+end
+
+num_string
+end
+
+puts english_number(999)
+puts english_number(4352)  

ch10-nothing-new/ninety_nine_bottles_of_beer.rb

@@ -1 +1,75 @@
-# your code here
+# your code heredef english_number number
+  if number <0
+    return 'Please enter a number that isn\'t negative'
+  end
+  if number ==0
+    return 'zero'
+  end
+
+  num_string =""
+
+  ones_place = ['one','two','three','four','five','six','seven','eight','nine']
+  tens_place = ['ten','twenty','thirty','fourty','fifty','sixty','seventy','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',39],
+['duodecillion',39],['tredecillion',42],['quattuordecillion',45],['quindecillion',48],
+['sexdecillion',51],['septendectillion',54],['octodecillion',57],['novemdecillion',60],
+['vigintillion',63],['googol',100]]
+
+#'left' is how much left of the number we still have t write
+#'write' is the part we are writing out right now
+
+left = number
+while zillions.length >0
+  zil_pair = zillions.pop
+  zil_name = zil_pair[0]
+  zil_base = 10 ** zil_pair[1]
+  write = left /zil_base
+  left = left - write*zil_base
+
+if write > 0
+  prefix =english_number write
+  num_string = num_string + prefix + ' ' + zil_name
+  if left > 0
+    num_string = num_string +' '
+  end
+end
+
+write = left/10
+left = left -write*10
+
+if write >0
+  if write ((write ==1) and (left >0))
+    num_string =num_string + teenagers[left-1]
+    left =0
+  else
+    num_string = num_string + tens_place[write-1]
+  end
+end
+
+write=left
+left=0
+if write >0
+  num_string = num_string+ones_place[write-1]
+end
+
+num_string
+end
+
+num_at_start = 5
+num_now = num_at_start
+while num_now >2
+  puts enlgish_number(num_now).capitalize + ' bottles of beer on the wall, ' +
+    english_number(num_now) + 'bottles of beer!'
+    num_now = num_now -1
+    puts 'Take one 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!"
+  puts "Take one down, pass it around, one bottle of beer on the wall!"
+  puts "One bottle of beer on the wall, one bottle of beer!"
+  puts "take one down, pass it around, no more bottles of beer on the wall!"

ch10-nothing-new/shuffle.rb

@@ -1,3 +1,4 @@
 def shuffle arr
-  # your code here
-end
+  arr.sort_by{rand}
+end
+puts shuffle(['this', 'is', 'a','shuffle','test'])

ch10-nothing-new/sort.rb

@@ -1,3 +1,25 @@
 def sort arr
-  # your code here
-end
+  rec_sort arr, []
+end
+
+def rec_sort unsorted, sorted
+  if unsorted.length <=0
+    return sorted
+  end
+
+  smallest = unsorted.pop
+  still_unsorted = []
+
+  unsorted.each do |word|
+    if word < smallest
+      still_unsorted.push smallest
+      smallest = word
+    else
+      still_unsorted.push word
+    end
+  end
+
+  sorted.push smallest
+  rec_sort still_unsorted, sorted
+end
+puts(sort(['can','feel','singing','like','a','can']))

ch11-reading-and-writing/build_a_better_playlist.rb

@@ -1,3 +1,58 @@
 def music_shuffle filenames
-  # your code here
+  songs_and_paths = filenames.map do |s|
+    [s, s.split('/')] # [song, path]
+  end
+
+  tree = {:root => []}
+
+  # put each song into the tree
+  insert_into_tree = proc do |branch, song, path|
+    if path.length == 0 # add to current branch
+      branch[:root] << song
+    else # delve deeper
+      sub_branch = path[0]
+      path.shift # like "pop", but pops off the front
+
+      if !branch[sub_branch]
+        branch[sub_branch] = {:root => []}
+      end
+
+      insert_into_tree[branch[sub_branch], song, path]
+    end
+  end
+
+  songs_and_paths.each{|sp| insert_into_tree[tree, *sp]}
+
+  # recursively:
+  # - shuffle sub-branches (and root)
+  # - weight each sub-branch (and root)
+  # - merge (shuffle) these groups together
+  shuffle_branch = proc do |branch|
+    shuffled_subs = []
+
+    branch.each do |key, unshuffled|
+      shuffled_subs << if key == :root
+      unshuffled # At this level, these are all duplicates.
+      else
+        shuffle_branch[unshuffled]
+      end
+    end
+
+    weighted_songs = []
+
+    shuffled_subs.each do |shuffled_songs|
+      shuffled_songs.each_with_index do |song, idx|
+        num = shuffled_songs.length.to_f
+        weight = (idx + rand) / num
+        weighted_songs << [song, weight]
+      end
+    end
+
+    weighted_songs.sort_by{|s,v| v}.map{|s,v| s}
+  end
+  shuffle_branch[tree]
 end
+
+# songs = ['aa/bbb', 'aa/ccc', 'aa/ddd',
+#          'AAA/xxxx', 'AAA/yyyy', 'AAA/zzzz', 'foo/bar']
+# puts(music_shuffle(songs))

ch11-reading-and-writing/build_your_own_playlist.rb

@@ -1 +1,9 @@
-# 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 'Done!'