Minor style fixes

Author: Dbz

.rubocop.yml

@@ -12,6 +12,11 @@ Metrics/MethodLength:
   CountComments: false  # count full line comments?
   Max: 20
 
+Metrics/BlockLength:
+  Enabled: true
+  Exclude:
+    - spec/**/*
+
 Style/ExtraSpacing:
   AllowForAlignment: true
   ForceEqualSignAlignment: true
@@ -22,6 +27,9 @@ Style/FrozenStringLiteralComment:
 Style/TrailingBlankLines:
   Enabled: false
 
+Style/TernaryParentheses:
+  Enabled: false
+
 AllCops:
   TargetRubyVersion: 2.3
   DisplayCopNames: true

algorithms/animal_shelter.rb

@@ -31,6 +31,7 @@ def enqueue(animal)
   def dequeue_any
     return @dog_queue.pop if @cat_queue.last.nil?
     return @cat_queue.pop if @dog_queue.last.nil?
+
     @cat_queue.first.shelter_number < @dog_queue.first.shelter_number ? @cat_queue.shift : @dog_queue.shift
   end
 

algorithms/sort_stack.rb

@@ -1,7 +1,7 @@
 # CtCI 6th Edition Problem 3.5
 # Sort Stack: Write a program to sort a stack such that the smallest items are on the top. You can use
 # an additional temporary stack, but you may not copy the elements into any other data structure
-# (such as an array). The stack supports the following operations: push, pop, peek, and isEmpty. 
+# (such as an array). The stack supports the following operations: push, pop, peek, and isEmpty.
 
 class Stack
   attr_reader :size
@@ -17,7 +17,8 @@ def push(el)
   end
 
   def pop
-    return nil if is_empty?
+    return nil if empty?
+
     @size -= 1
     @stack.pop
   end
@@ -26,24 +27,24 @@ def peek
     @stack.last
   end
 
-  def is_empty?
+  def empty?
     @size.zero?
   end
 
   # Sorts so that the smallest items are on top
-  # 
+  # Pops each element, and potentially pops each element back. Worst cash O(n^2) time complexity. 
   def sort
-    return self if is_empty?
+    return self if empty?
+
     temp = Stack.new
     temp.push pop
-    until is_empty?
+
+    until empty?
       el = pop
-      if el <= temp.peek
-        temp.push el
-      else
-        push temp.pop until temp.is_empty? || temp.peek <= el
-        temp.push el
+      if el > temp.peek
+        push temp.pop until temp.empty? || temp.peek <= el
       end
+      temp.push el
     end
     temp
   end

data-structures/queue_using_two_stacks.rb

@@ -1,5 +1,5 @@
 # CtCI 6th Edition Problem 3.4
-# Queue via Stacks: Implement a MyQueue class which implements a queue using two stacks. 
+# Queue via Stacks: Implement a MyQueue class which implements a queue using two stacks.
 
 class Stack
   attr_reader :size
@@ -34,8 +34,9 @@ def add(item)
   # Then return what is popped from the pop stack which is the first element added to the queue.
   # Then pop the pop stack back onto the push stack reversing the data again to how it was.
   # O(n) operation
-  def remove()
+  def remove
     return nil if @push_stack.size.zero?
+
     @push_stack.size.times { @pop_stack.push @push_stack.pop }
     @pop_stack.pop.tap { @pop_stack.size.times { @push_stack.push @pop_stack.pop } }
   end

data-structures/set_of_stacks.rb

@@ -6,7 +6,7 @@
 # SetOfStacks. push () and SetOfStacks. pop () should behave identically to a single stack
 # (that is, pop ( ) should return the same values as it would if there were just a single stack).
 # FOLLOW UP
-# Implement a function popAt (int index) which performs a pop operation on a specific sub-stack. 
+# Implement a function popAt (int index) which performs a pop operation on a specific sub-stack.
 
 class Stack
   def initialize
@@ -39,8 +39,9 @@ def push(el)
   end
 
   def pop
-    return nil if @stacks.size == 1 && @last_size.last == 0
-    if @last_size.last == 0
+    return nil if @stacks.size == 1 && @last_size.last.zero?
+
+    if @last_size.last.zero?
       @stacks.pop
       @last_size.pop
     end
@@ -50,6 +51,7 @@ def pop
 
   def pop_at(index)
     return nil if @last_size[index].zero?
+
     @last_size[index] -= 1
     @stacks[index].pop
   end