Learn to Program exercises

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

@@ -1,3 +1,34 @@
 def ask question
-  # your code here
-end
+  while true
+    puts question
+    reply = gets.chomp.downcase
+
+    if (reply == "yes") || (reply == "no")
+      if reply == "yes"
+        return true
+      else
+        return false
+      end
+      break
+    else
+      puts 'Please answer "yes" or "no".'
+    end
+  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?"
+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 "DEBRIEFING:"
+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
+
+  old_roman = ""
+
+  old_roman = old_roman + "M" * (num / 1000)
+  old_roman = old_roman + "D" * (num % 1000 / 500)
+  old_roman = old_roman + "C" * (num % 500 / 100)
+  old_roman = old_roman + "L" * (num % 100 / 50)
+  old_roman = old_roman + "X" * (num % 50 / 10)
+  old_roman = old_roman + "V" * (num % 10 / 5)
+  old_roman = old_roman + "I" * (num % 5 / 1)
+
+  old_roman
+
+end

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

@@ -1,3 +1,38 @@
 def roman_numeral num
-  # your code here
-end
+  new_roman = ""
+
+  thousands = num / 1000
+  hundreds = num % 1000 / 100
+  tens = num % 100 / 10
+  ones = num % 10
+
+  new_roman = "M" * thousands
+
+  if hundreds == 9
+    new_roman = new_roman + "CM"
+  elsif hundreds == 4
+    new_roman = new_roman + "CD"
+  else
+    new_roman = new_roman + "D" * (num % 1000 / 500)
+    new_roman = new_roman + "C" * (num % 500 / 100)
+  end
+
+  if tens == 9
+    new_roman = new_roman + "XC"
+  elsif tens == 4
+    new_roman = new_roman + "XL"
+  else
+    new_roman = new_roman + "L" * (num % 100 / 50)
+    new_roman = new_roman + "X" * (num % 50 / 10)
+  end
+
+  if ones == 9
+    new_roman = new_roman + "IX"
+  elsif ones == 4
+    new_roman = new_roman + "IV"
+  else
+    new_roman = new_roman + "V" * (num % 10 / 5)
+    new_roman = new_roman + "I" * (num % 5)
+  end
+    new_roman
+end

ch10-nothing-new/dictionary_sort.rb

@@ -1,3 +1,27 @@
 def dictionary_sort arr
-  # your code here
-end
+  rec_dic_sort arr, []
+end
+
+def rec_dic_sort unsorted, sorted
+
+  if unsorted.length < 1
+    return sorted
+  end
+
+  still_unsorted = []
+  smallest = unsorted.pop  # smallest placeholder item
+
+  unsorted.each do |i|
+    if i.downcase < smallest.downcase
+      still_unsorted << smallest
+      smallest = i
+    else
+      still_unsorted << i
+    end
+  end
+
+  sorted << smallest
+  rec_dic_sort still_unsorted, sorted
+
+end
+

ch10-nothing-new/english_number.rb

@@ -1,3 +1,62 @@
 def english_number number
-  # your code here
-end
+   if number < 0
+     return "Please eneter 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", "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 = 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
+   end
+
+
+  write = left / 10
+  left = left - write * 10
+
+  if write > 0
+    if ((write == 1) and (left > 0))
+      num_string = num_string + teenagers[left-1]
+      left = 0
+    else
+      num_string = num_string + tens_place[write-1]
+    end
+    if left > 0
+      num_string = num_string + "-"
+    end
+  end
+
+  write = left
+  left = 0
+
+  if write > 0
+    num_string = num_string + ones_place[write-1]
+  end
+
+  num_string
+
+end

ch10-nothing-new/ninety_nine_bottles_of_beer.rb

@@ -1 +1,112 @@
-# your code here
+def 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", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
+   teenagers =  ["eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]
+
+   left = number
+   write = left / 1000000000000  # how many trllions?
+   left = left - write * 1000000000000 # substract the millions
+
+   if write > 0
+     trillions = english_number write # recursion!
+     num_string = num_string + trillions + " trillion"
+     if left > 0
+       num_string = num_string + " "
+     end
+   end
+
+   write = left / 1000000000  # how many billions?
+   left = left - write * 1000000000 # substract the billions
+
+   if write > 0
+     billions = english_number write # recursion!
+     num_string = num_string + billions + " billion"
+     if left > 0
+       num_string = num_string + " "
+     end
+   end
+
+
+   write = left / 1000000  # how many millions?
+   left = left - write * 1000000 # substract the millions
+
+   if write > 0
+     millions = english_number write # recursion!
+     num_string = num_string + millions + " million"
+     if left > 0
+       num_string = num_string + " "
+     end
+   end
+
+   write = left / 1000  # how many thousands?
+   left = left - write * 1000  # substract the thousands
+
+   if write > 0
+     thousands = english_number write # recursion!
+     num_string = num_string + thousands + " thousand"
+     if left > 0
+       num_string = num_string + " "
+     end
+   end
+
+   write = left / 100  # how many hundreds?
+   left = left - write * 100  # substract the hundreds
+
+   if write > 0
+     hundreds = english_number write # recursion!
+     num_string = num_string + hundreds + " hundred"
+     if left > 0
+       num_string = num_string + " "
+     end
+   end
+
+  write = left / 10
+  left = left - write * 10
+
+  if write > 0
+    if ((write == 1) and (left > 0))
+      num_string = num_string + teenagers[left-1]
+      left = 0
+    else
+      num_string = num_string + tens_place[write-1]
+    end
+    if left > 0
+      num_string = num_string + "-"
+    end
+  end
+
+  write = left
+  left = 0
+
+  if write > 0
+    num_string = num_string + ones_place[write-1]
+  end
+
+  num_string
+
+end
+
+bbottles = 99
+
+while bbottles >1
+  bb_eng = english_number bbottles
+  bb_next = english_number (bbottles-1)
+  puts (bb_eng + " bottles of beer on the wall, " + bb_eng + " bottles of beer!").capitalize
+  puts "Take one down and pass it around, " + bb_next + " bottles of beer on the wall!"
+  puts
+  bbottles -=1
+end
+  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 +1,13 @@
-def shuffle arr
-  # your code here
+def shuffle (array)
+  shuffled = []
+  if array.length == 0
+    return array
+  else
+    while array.length > 0
+      n = rand(array.length - 1)
+      shuffled << array[n]
+      array.delete_at(n)
+    end
+  end
+    shuffled
 end

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 < 1
+    return sorted
+  end
+
+  still_unsorted = []
+  smallest = unsorted.pop  # smallest placeholder item
+
+  unsorted.each do |i|
+    if i < smallest
+      still_unsorted << smallest
+      smallest = i
+    else
+      still_unsorted << i
+    end
+  end
+
+  # this returns smallest item,store it in sorted and use recursion to find the next smallest item. 
+
+  sorted << smallest
+  rec_sort still_unsorted, sorted
+
+end
+