Learn to program Laurent

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

@@ -1,3 +1,12 @@
-def ask question
-  # your code here
-end
+def ask question 
+  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 
+  end

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

@@ -1,3 +1,13 @@
 def old_roman_numeral num
-  # your code here
-end
+
+thousand = 'M' * (num / 1000)
+fivehundreds = thousand + 'D' * (num % 1000 / 500)
+hundreds = fivehundreds + 'C' * (num % 500 / 100)
+fifties = hundreds + 'L' * (num % 100 / 50)
+tenth = fifties + 'X' * (num % 50 / 10)
+fifth = tenth + 'V' * (num % 10 / 5)
+units = fifth + 'I' * (num % 5 / 1)
+
+units
+
+end

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

@@ -1,3 +1,36 @@
 def roman_numeral num
-  # your code here
-end
+thousand = num / 1000
+hundreds = num % 1000 / 100
+tenth = num % 100 / 10
+units = num % 10
+
+roman = 'M' * thousand
+
+	if hundreds == 9
+		roman = roman +'CM'
+	elsif hundreds == 4
+		roman = roman + 'CD'
+	else
+		roman = roman + 'D' * (num % 1000 / 500)
+		roman = roman + 'C' * (num % 500 / 100)
+	end
+
+	if tenth == 9
+		roman = roman + 'XC'
+	elsif tenth == 4
+		roman = roman +'XL'
+	else
+		roman = roman + 'L' * (num % 100 / 50)
+		roman = roman + 'X' * (num % 50 / 10)
+	end
+
+	if units == 9
+		roman = roman + 'IX'
+	elsif units == 4
+		roman = roman + 'IV'
+	else
+		roman = roman + 'V' * (num % 10 / 5)
+		roman = roman + 'I' * (num % 5 / 1)	
+	end
+end
+

ch10-nothing-new/dictionary_sort.rb

@@ -1,3 +1,21 @@
 def dictionary_sort arr
-  # your code here
+rec_dict_sort arr, []
+end
+
+def rec_dict_sort unsorted, sorted
+    if unsorted.length <= 0
+    return sorted
+    end
+smallest = unsorted.pop
+still_unsorted = []
+unsorted.each do |tested_object|
+    if tested_object.downcase < smallest.downcase
+    still_unsorted.push smallest
+    smallest = tested_object
+    else
+    still_unsorted.push tested_object
+    end
+end
+sorted.push smallest
+rec_dict_sort still_unsorted, sorted
 end

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', '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 +1,10 @@
-# your code here
+num_at_start = 9999
+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 +1,20 @@
 def shuffle arr
-  # your code here
+	final_array = []
+	while arr.length > 0
+		rand_index = rand(arr.length)
+		intial_index = 0
+		array = []
+		arr.each do |w|
+				if intial_index == rand_index
+					final_array.push(w)
+				else
+					array.push(w)
+				end
+
+				intial_index = intial_index + 1
+				end
+	arr = array
+	end
+
+return final_array
 end

ch10-nothing-new/sort.rb

@@ -1,3 +1,24 @@
-def sort arr
-  # your code here
+def sort arr 
+rec_sort arr, [] 
+end 
+
+def rec_sort unsorted, sorted 
+	if unsorted.length <= 0 
+		return sorted 
+	end
+
+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
+
+sorted.push smallest 
+rec_sort still_unsorted, sorted 
 end

ch11-reading-and-writing/build_a_better_playlist.rb

@@ -1,3 +1,38 @@
 def music_shuffle filenames
-  # your code here
+   filenames = filenames.sort
+  len = filenames.length
+
+   2.times do
+    l_idx = 0 # index of next card in left pile
+    r_idx = len/2 # index of next card in right pile
+    shuf = []
+    # NOTE: If we have an odd number of "cards",
+    # then the right pile will be larger.
+
+    while shuf.length < len
+      if shuf.length%2 == 0
+        # take card from right pile
+        shuf.push(filenames[r_idx])
+        r_idx = r_idx + 1
+      else
+        # take card from left pile
+        shuf.push(filenames[l_idx])
+        l_idx = l_idx + 1
+      end
+    end
+
+    filenames = shuf
+  end
+
+  arr = []
+  cut = rand(len) # index of card to cut at
+  idx = 0
+
+  while idx < len
+    arr.push(filenames[(idx+cut)%len])
+    idx = idx + 1
+  end
+
+  arr
 end
+

ch11-reading-and-writing/build_your_own_playlist.rb

@@ -1 +1,6 @@
-# your code here
+musics = shuffle(Dir['**/*.mp3']) 
+File.open 'playlist.m3u', 'w' do |f| 
+musics.each do |mp3| 
+f.write mp3+"\n" 
+end 
+end

ch11-reading-and-writing/safer_picture_downloading.rb

@@ -1 +1,24 @@
-# your code here
+Dir.chdir 'C:\Users\Laurent\Downloads' 
+pic_names = Dir['*.jpg']
+
+puts 'What would you like to call this batch?' 
+batch_name = gets.chomp 
+puts 
+print "Downloading #{pic_names.length} files: "
+
+pic_number = 1 
+pic_names.each do |name| 
+print '.' 
+if pic_number < 10 
+	new_name = "#{batch_name}0#{pic_number}.jpg" 
+else 
+	new_name = "#{batch_name}#{pic_number}.jpg" 
+end
+
+if File.exist?(new_name) == false
+File.rename name, new_name
+elsif File.exist?(new_name) == true
+	exit
+end
+pic_number = pic_number + 1 
+end 

ch12-new-classes-of-objects/birthdates.txt

@@ -0,0 +1,8 @@
+Christopher Alexander, Oct 4, 1936
+Christopher Lambert, Mar 29, 1957
+Christopher Lee, May 27, 1922
+Christopher Lloyd, Oct 22, 1938
+Christopher Pine, Aug 3, 1976
+Christopher Plummer, Dec 13, 1927
+Christopher Walken, Mar 31, 1943
+The King of Spain, Jan 5, 1938

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

@@ -1 +1,14 @@
-# your code here
+birth_dates = {}
+File.read('birthdates.txt').each_line do |line|
+  line = line.chomp
+  comma = line.index(',') 
+$name = line[0..(comma - 1)] 
+$dob = line[-12..-1]
+ birth_dates[$name] = $dob
+end
+ puts "Enter a name"
+ name = gets.chomp
+  puts (birth_dates[name])[0..5] 
+
+
+

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

@@ -1 +1,23 @@
-# your code here
+puts "Enter your birth year in the following format: YYYY"
+year = gets.chomp.to_i
+puts "Enter your birth month in the following format: MM"
+month = gets.chomp.to_i
+puts "Enter your birth day in the following format: DD"
+day = gets.chomp.to_i
+
+y = Time.new.year - year
+m = Time.new.month - month
+d = Time.new.day - day
+ if m - month > 0 
+puts "You are #{y}years old"
+puts "SPANK!" * y
+elsif m -month == 0 and d - day >= 0
+puts "You are #{y}years old"
+puts "SPANK!" * y
+elsif m -month == 0 and d - day < 0
+puts "You are #{y-1}years old"
+puts "SPANK!" * (y-1)
+elsif m-month < 0
+puts "You are #{y-1}years old"
+puts "SPANK!" * (y-1)
+end

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

@@ -1 +1,2 @@
-# your code here
+billion_seconds = (Time.local(1976, 8, 15, 21) + 3600) + 1000000000
+puts billion_seconds

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

@@ -1,3 +1,30 @@
 def roman_to_integer roman
-  # your code here
+  digit_vals = {'i' => 1,
+                'v' => 5,
+                'x' => 10,
+                'l' => 50,
+                'c' => 100,
+                'd' => 500,
+                'm' => 1000}
+  total = 0
+  prev = 0
+  index = roman.length - 1
+  while index >= 0
+    c = roman[index].downcase
+    index = index - 1
+    val = digit_vals[c]
+    if !val
+      puts 'This is not a valid roman numeral!'
+      return
+    end
+
+    if val < prev
+      val = val * -1
+    else
+      prev = val
+    end
+    total = total + val
+  end
+
+  total
 end