Chris Pine Ch9-14

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

@@ -1,3 +1,29 @@
 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
+
+  answer # This is the return of true or false
+end
+puts 'Hello, and thank you for...'
+puts
+ask 'Do you like eating tacos?'
+ask 'Do you like eating burrittos?'
+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 drinking horchata?'
+ask 'Do you like eating flautas?'
+
+puts
+puts 'DEBREIFING:'
+puts 'Thank you for...'
+puts
+puts wets_bed

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

@@ -1,3 +1,15 @@
 def old_roman_numeral num
-  # your code here
-end
+  numeral = ''
+
+  numeral = numeral + 'M' * (num / 1000)
+  numeral = numeral + 'D' * (num % 1000 / 500)
+  numeral = numeral + 'C' * (num % 500 / 100)
+  numeral = numeral + 'L' * (num % 100 / 50)
+  numeral = numeral + 'X' * (num % 50 / 10)
+  numeral = numeral + 'V' * (num % 10 / 5)
+  numeral = numeral + 'I' * (num % 5 / 1)
+
+  numeral
+end
+
+puts old_roman_numeral(2016)

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

@@ -1,3 +1,38 @@
 def roman_numeral num
-  # your code here
-end
+    thousand = (num / 1000)
+    hundred = (num % 1000 / 100)
+    ten = (num % 100 / 10)
+    one = (num % 10)
+
+    numeral = 'M' * thousand
+
+    if hundred == 9
+      numeral = numeral + 'CM'
+    elsif hundred == 4
+      numeral = numeral + 'CD'
+    else
+      numeral = numeral + 'D' * (num % 1000 / 500)
+      numeral = numeral + 'C' * (num % 500 / 100)
+    end
+
+    if ten == 9
+      numeral = numeral + 'XC'
+    elsif ten == 4
+      numeral = numeral + 'XL'
+    else
+      numeral = numeral + 'L' * (num % 100 / 50)
+      numeral = numeral + 'X' * (num % 50 / 10)
+    end
+
+    if one == 9
+      numeral = numeral + 'IX'
+    elsif numeral == 4
+      numeral = numeral = 'IV'
+    else
+      numeral = numeral + 'V' * (num % 10 / 5)
+      numeral = numeral + 'I' * (num % 5 / 1)
+    end
+    numeral
+end
+
+puts roman_numeral(2016)

ch10-nothing-new/dictionary_sort.rb

@@ -1,3 +1,12 @@
 def dictionary_sort arr
-  # your code here
-end
+  return arr if arr.length <= 1
+
+  middle = arr.pop
+  less = arr.select{|x| x.downcase < middle.downcase}
+  more = arr.select{|x| x.downcase >= middle.downcase}
+
+dictionary_sort(less) + [middle] + dictionary_sort(more)
+end
+
+words = ['hakuna', 'Matata', 'what', 'a', 'wonderful', 'phrase']
+puts(dictionary_sort(words).join(' '))

ch10-nothing-new/english_number.rb

@@ -1,3 +1,105 @@
 def english_number number
-  # your code here
+  if number < 0 # No negative numbers.
+    return 'Please enter a number that isn\'t negative.'
+  end
+
+  if number == 0
+    return 'zero'
+  end
+
+# No more special cases! No more returns!
+num_string = '' # This is the string we will return.
+ones_place = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']
+tens_place = ['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]]
+# "left" is how much of the number we still have left to write out.
+# "write" is the part we are writing out right now.
+# write and left!!
+
+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 # How many zillions left?
+    left = left - write*zil_base # Subtract off those zillions.
+
+    if write > 0
+      # Now here's the recursion:
+      prefix = english_number write
+      num_string = num_string + prefix + ' ' + zil_name
+
+      if left > 0
+      # So we don't write 'two billionfifty-one'...
+      num_string = num_string + ' '
+      end
+    end
+  end
+
+write = left/100 # How many hundreds left?
+left = left - write*100 # Subtract off those hundreds.
+  if write > 0
+# Now here's the recursion:
+    hundreds = english_number write
+    num_string = num_string + hundreds + ' hundred'
+
+    if left > 0
+# So we don't write 'two hundredfifty-one'...
+      num_string = num_string + ' '
+    end
+  end
+
+write = left/10 # How many tens left?
+left = left - write*10 # Subtract off those tens.
+
+if write > 0
+if ((write == 1) and (left > 0))
+# Since we can't write "tenty-two" instead of "twelve", we have to make a special exception
+# for these.
+num_string = num_string + teenagers[left-1]
+# The "-1" is because teenagers[3] is 'fourteen', not 'thirteen'.
+
+# Since we took care of the digit in the # ones place already, we have nothing left to write.
+left = 0
+  else
+    num_string = num_string + tens_place[write-1]
+# The "-1" is because tens_place[3] is 'forty', not 'thirty'.
+  end
+
+      if left > 0
+        # So we don't write 'sixtyfour'...
+        num_string = num_string + '-'
+      end
+    end
+
+write = left # How many ones left to write out?
+left = 0 # Subtract off those ones.
+
+if write > 0
+num_string = num_string + ones_place[write-1]
+# The "-1" is because ones_place[3] is 'four', not 'three'.
 end
+# Now we just return "num_string"...
+num_string
+end
+
+puts english_number( 0)
+puts english_number( 9)
+puts english_number( 10)
+puts english_number( 11)
+puts english_number( 17)
+puts english_number( 32)
+puts english_number( 88)
+puts english_number( 99)
+puts english_number(100)
+puts english_number(101)
+puts english_number(234)
+puts english_number(3211)
+puts english_number(999999)
+puts english_number(1000000000000)

ch10-nothing-new/ninety_nine_bottles_of_beer.rb

@@ -1 +1,78 @@
-# your code here
+# def english_number number
+  if number < 0 # No negative numbers.
+    return 'Please enter a number that isn\'t negative.'
+  end
+
+  if number == 0
+    return 'zero'
+  end
+
+# No more special cases! No more returns!
+num_string = '' # This is the string we will return.
+ones_place = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']
+tens_place = ['ten', 'twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety']
+teenagers = ['eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen']
+
+# "left" is how much of the number
+# we still have left to write out.
+# "write" is the part we are
+# writing out right now.
+# write and left...get it? :)
+
+left = number
+write = left/100 # How many hundreds left?
+left = left - write*100 # Subtract off those hundreds.
+  if write > 0
+# Now here's the recursion:
+    hundreds = english_number write
+    num_string = num_string + hundreds + ' hundred'
+
+    if left > 0
+# So we don't write 'two hundredfifty-one'...
+      num_string = num_string + ' '
+    end
+  end
+
+write = left/10 # How many tens left?
+left = left - write*10 # Subtract off those tens.
+
+if write > 0
+if ((write == 1) and (left > 0))
+# Since we can't write "tenty-two" instead of "twelve", we have to make a special exception
+# for these.
+num_string = num_string + teenagers[left-1]
+# The "-1" is because teenagers[3] is 'fourteen', not 'thirteen'.
+
+# Since we took care of the digit in the # ones place already, we have nothing left to write.
+left = 0
+  else
+    num_string = num_string + tens_place[write-1]
+# The "-1" is because tens_place[3] is 'forty', not 'thirty'.
+  end
+
+      if left > 0
+        # So we don't write 'sixtyfour'...
+        num_string = num_string + '-'
+      end
+    end
+
+write = left # How many ones left to write out?
+left = 0 # Subtract off those ones.
+
+if write > 0
+num_string = num_string + ones_place[write-1]
+# The "-1" is because ones_place[3] is 'four', not 'three'.
+end
+# Now we just return "num_string"...
+num_string
+end
+
+num_at_start = 10 # change to 9999 if you want
+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 = num_now - 1
+  puts 'Take one down, pass it around, ' +
+    english_number(num_now) + ' bottles of beer on the wall!'
+end

ch10-nothing-new/shuffle.rb

@@ -1,3 +1,26 @@
 def shuffle arr
-  # your code here
-end
+  shuf = []
+#shuffle an array of any size above zero
+  while arr.length > 0
+    rand_index = rand(arr.length)
+#iterate each item placing all bar the random one in the new array which goes into shuf
+    curr_index = 0
+    new_arr = []
+
+    arr.each do |item|
+      if curr_index == rand_index
+        shuf.push item
+      else
+        new_arr.push item
+      end
+
+      curr_index = curr_index + 1
+    end
+      #call back new array instead of original array
+      arr = new_arr
+    end
+
+  shuf
+end
+
+puts(shuffle([1,9,2,8,3,7,4,6,5]))

ch10-nothing-new/sort.rb

@@ -1,3 +1,29 @@
 def sort arr
-  # your code here
-end
+    rec_sort arr, []
+  end
+
+  def rec_sort unsorted, sorted
+    if unsorted.length <= 0
+      return sorted
+    end
+    # So if we got here, then it means we still # have work to do.
+    smallest = unsorted.pop
+    still_unsorted = []
+
+    unsorted.each do |tested_object|
+      if tested_object < smallest
+        still_unsorted.push smallest
+        smallest = tested_object
+      else
+        still_unsorted.push tested_object
+      end
+    end
+
+    # Now "smallest" really does point to the
+    # smallest element that "unsorted" contained,
+    # and all the rest of it is in "still_unsorted". l
+    sorted.push smallest
+
+    rec_sort still_unsorted, sorted
+  end
+puts(sort([' can' ,' feel' ,' singing' ,' like' ,' a' ,' can' ]))