ruby week 1

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

@@ -1,3 +1,13 @@
-def ask question
-  # your code here
+def ask question 
+
+	while true
+	  puts question
+	  reply = gets.chomp.downcase
+
+	  if (reply == 'yes' || reply == 'no')
+	  	return reply == 'yes'
+	  else
+			puts 'Please answer "yes" or "no".'  
+		end
+	end
 end

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

@@ -1,3 +1,17 @@
 def old_roman_numeral num
-  # your code here
+ 	romans    = ['I',  'V',  'X',  'L',   'C',   'D',    'M']
+  values    = [ 1,    5,   10,   50,   100,   500,   1000 ]
+  result    = ''
+
+  values.select!{ |v| v <= num }
+
+  (values.length-1).downto(0) { |i|
+    max_num = values[i]
+    (num / max_num).times { 
+      result += romans[i]
+      num -= max_num
+    }
+  }
+
+  return result
 end

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

@@ -1,3 +1,20 @@
 def roman_numeral num
-  # your code here
+	roman_letters = "IVXLCDM"
+  mods = {:C => 100, :X => 10, :I => 1}
+
+  roman = 'M' * (num / 1000)
+
+  mods.each do |k, v|
+  	digit = num % (10 * v) / v
+  	id = roman_letters.index(k.to_s)
+
+  	if (digit == 9) || (digit == 4)
+  		roman += k.to_s + (digit == 9 ? roman_letters[id+2] : roman_letters[id+1])
+  	else
+  		roman += roman_letters[id+1] * (num % (10 * v) / (5 * v))
+  		roman += roman_letters[id] * (num % (5 * v) / v)
+  	end
+  end
+
+	roman
 end

ch10-nothing-new/dictionary_sort.rb

@@ -1,3 +1,22 @@
 def dictionary_sort arr
-  # your code here
+  recursive_sort arr, []
+end
+
+def recursive_sort unsorted_array, sorted_array
+  smallest_id = 0
+
+  (unsorted_array.length-1).times { |i|
+    if unsorted_array[smallest_id].downcase > unsorted_array[i+1].downcase
+      smallest_id = i+1
+    end
+  }
+
+  sorted_array.push(unsorted_array[smallest_id])
+  unsorted_array.delete_at(smallest_id)
+
+  if unsorted_array.length > 0
+    recursive_sort unsorted_array, sorted_array
+  else
+    return sorted_array
+  end
 end

ch10-nothing-new/english_number.rb

@@ -1,3 +1,68 @@
 def english_number number
-  # your code here
-end
+	if number < 0
+		return 'Please enter a number that isn\'t negative.' 
+	elsif 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']
+
+	big_numbers = { :quindecillion => 10**48,			:quattuordecillion => 10**45, :tredecillion => 10**42,	
+									:duodecillion => 10**39,			:undecillion => 10**36, 			:decillion => 10**33,			
+									:nonillion => 10**30,					:octillion => 10**27,					:septillion => 10**24,
+									:sextillion => 10**21,				:quintillion => 10**18,				:quadrillion => 10**15,		
+									:trillion => 10**12,					:billion => 10**9,						:million => 1_000_000,
+									:thousand => 1000,		 				:hundred => 100																			}
+
+	left = number
+
+	big_numbers.each do |word, num|
+		write = left / num
+		left = left - write * num
+
+		if write > 0
+			numbers = english_number write
+			num_string = num_string + numbers + " #{word}" 
+
+			if left > 0
+		    num_string = num_string + ' '
+			end
+		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"
+      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 + '-' # So we don't write 'sixtyfour'... 
+		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]
+	end
+
+	num_string
+end

ch10-nothing-new/ninety_nine_bottles_of_beer.rb

@@ -1 +1,11 @@
-# your code here
+load 'english_number.rb'
+
+num_at_start = 21 # change to 9999 if you want
+
+num_at_start.downto(1) do |num_now|
+  puts english_number(num_now).capitalize + " bottle#{num_now==1 ? '' : 's'} of beer on the wall, " +
+    english_number(num_now) + " bottle#{num_now==1 ? '' : 's'} of beer!"
+
+  puts "Take one down, pass it around, " +
+     (num_now == 1 ? 'no more' : english_number(num_now-1)) + " bottle#{num_now == 2 ? '' : 's'} of beer on the wall!"
+end

ch10-nothing-new/shuffle.rb

@@ -1,3 +1,5 @@
 def shuffle arr
-  # your code here
+  arr.shuffle!
+  half = arr.length / 2
+  arr = arr.slice(0, half).shuffle + arr.slice(half, arr.length).shuffle
 end

ch10-nothing-new/sort.rb

@@ -1,3 +1,19 @@
 def sort arr
-  # your code here
+  recursive_sort arr, []
+end
+
+def recursive_sort unsorted_array, sorted_array
+  smallest_id = 0
+
+  (unsorted_array.length-1).times { |i|
+    smallest_id = i+1 if unsorted_array[smallest_id] > unsorted_array[i+1]
+  }
+
+  sorted_array.push(unsorted_array.delete_at(smallest_id))
+
+  if unsorted_array.length > 0
+    recursive_sort unsorted_array, sorted_array
+  else
+    return sorted_array
+  end
 end

ch11-reading-and-writing/build_a_better_playlist.rb

@@ -1,3 +1,94 @@
+#  This program finds all music files (.mp3, .wav, .aif) 
+#  in your chosen directory - 'MUSIC_PATH',
+#  and makes a SHUFFLED .m3u playlist.
+def shuffle arr
+  arr.shuffle!
+  half = arr.length / 2
+  arr = arr.slice(0, half).shuffle + arr.slice(half, arr.length).shuffle
+end
+
 def music_shuffle filenames
-  # your code here
+	filenames_arr = []
+	files_by_dir = {}
+
+	filenames.each do |name|
+		dir_name = name.split('/')[0...-1].join('/') #[0...-1] all but last element (/filename.xxx)
+
+		# create a hash, where key is directory name, and value is array of files in that dir..
+		files_by_dir[dir_name] ||= []
+		files_by_dir[dir_name] << name
+	end
+
+	# shuffle files in each directory
+	files_by_dir.each { |dir, arr| arr = shuffle(arr) }
+
+	new_list = []
+	filenames.length.times do |i|
+		# take one item from each shuffled directory
+		files_by_dir.each do |dir, arr|
+			if !arr.empty?
+				# and add it to the new list // first or last item for more variety
+				new_list.push( (i%2==0) ? arr.shift : arr.pop )
+			else
+				files_by_dir[dir].clear
+			end
+		end
+	end
+
+	new_list
+end
+
+def get_playlist_name
+	puts 'What would you like to call this playlist?'
+	playlist_name = ''
+	until playlist_name != ''
+		playlist_name = gets.chomp.strip
+		puts 'Please, enter a name' if playlist_name == ''
+	end
+	playlist_name = playlist_name + '.m3u'
+end
+
+def get_file_names path
+	file_names = Dir['./**/*.{mp3,wav,aif,aiff,m4a}']
+
+	if file_names.length == 0
+		puts "ERROR! Directory '#{path}' is empty!"
+		exit
+	end
+	file_names.sort! # sort alphabetically, as it first adds .mp3, then .wav and so on..
+end
+
+def change_dir_to path
+	if Dir[path].empty?
+		puts "ERROR! Directory '#{path}' not found!"
+		exit
+	end
+	Dir.chdir(path)
+end
+
+def make_playlist(playlist_name, files)
+	playlist_text = ""
+	files.each { |name| playlist_text << name + "\n" }
+
+	File.open playlist_name, 'w' do |f|
+	    f.write playlist_text
+	end
+
+	puts 
+	puts 'Done!'
 end
+
+#--------------------------- PROGRAM ---------------------------#
+MUSIC_PATH = '/Users/tadasmajeris/Music/GROSIU/- deep : house -'
+
+# Find if given path exists, change working directory to it
+change_dir_to MUSIC_PATH
+
+# Find all of the tracks to be moved and shuffle them
+file_names = music_shuffle(get_file_names MUSIC_PATH)
+
+# Get user to enter the playlist name
+playlist_name = get_playlist_name
+
+# Make the playlist, save it to .m3u
+make_playlist(playlist_name, file_names)

ch11-reading-and-writing/build_your_own_playlist.rb

@@ -1 +1,39 @@
-# your code here
+#  This program finds all music files (.mp3, .wav, .aif) 
+#  in your chosen directory - 'MUSIC_PATH',
+#  and makes a .m3u playlist from it.
+#  Tracks are sorted alphabetically
+
+MUSIC_PATH = '/Users/tadasmajeris/Downloads/nu electro'
+
+if Dir[MUSIC_PATH].empty?
+	puts "ERROR! Directory '#{MUSIC_PATH}' not found!"
+	exit
+end
+Dir.chdir(MUSIC_PATH)
+
+#  First we find all of the tracks to be moved.
+file_names = Dir['./**/*.{mp3,wav,aif}']
+
+if file_names.length == 0
+	puts "ERROR! Directory '#{MUSIC_PATH}' is empty!"
+	exit
+end
+file_names.sort! # sort alphabetically, as it first finds .mp3, then .wav
+
+puts 'What would you like to call this playlist?'
+playlist_name = ''
+until playlist_name != ''
+	playlist_name = gets.chomp.strip
+	puts 'Please, enter a name' if playlist_name == ''
+end
+playlist_name += '.m3u'
+
+playlist_text = ""
+file_names.each { |name| playlist_text << name + "\n" }
+
+File.open playlist_name, 'w' do |f|
+    f.write playlist_text
+end
+
+puts 
+puts 'Done!'

ch11-reading-and-writing/safer_picture_downloading.rb

@@ -1 +1,38 @@
-# your code here
+#  This program safely copies all .jpg from current directory to a chosen image_path
+image_path = './PictureInbox'
+if Dir[image_path].empty?
+	Dir.mkdir(image_path)
+end
+Dir.chdir(image_path)
+
+#  First we find all of the pictures to be moved.
+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 '.' # This is our "progress bar".
+	new_name = if pic_number < 10 
+		"#{batch_name}0#{pic_number}.jpg"
+	else
+		"#{batch_name}#{pic_number}.jpg" 
+	end
+
+
+	if !File.exist?(new_name) 
+		File.rename name, new_name
+		pic_number = pic_number + 1
+	else
+		puts "\n\n"
+		puts "ERROR! File '#{new_name}' already exists in #{Dir.pwd}"
+		exit
+	end
+end
+
+puts 
+puts 'Done!'

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

@@ -0,0 +1,4 @@
+Alice Winters,	Jan	5,	1989
+Tadas Majeris,	May 21,	1986
+John Lennon,		Oct 9,	1940
+Yoko Ono,				Feb 18,	1933