diff --git a/.DS_Store b/.DS_Store new file mode 100644 index 00000000..3af6d164 Binary files /dev/null and b/.DS_Store differ diff --git a/lib/problems.rb b/lib/problems.rb index 61bcaa5a..a3ca3e03 100644 --- a/lib/problems.rb +++ b/lib/problems.rb @@ -1,7 +1,25 @@ require_relative './stack.rb' def balanced(string) - raise NotImplementedError, "Not implemented yet" + return false if string.length % 2 != 0 + s_1 = Stack.new() + pairs = { + ")" => "(", + "}" => "{", + "]" => "[" + } + string.each_char do |val| + if pairs.values.include?(val) + s_1.push(val) + else + if pairs[val] == s_1.peak_last + s_1.pop + else + return false + end + end + end + return true if s_1.empty? end def evaluate_postfix(postfix_expression) diff --git a/lib/queue.rb b/lib/queue.rb index 828217c6..db29fb35 100644 --- a/lib/queue.rb +++ b/lib/queue.rb @@ -1,31 +1,60 @@ +QUEUE_SIZE = 20 + class Queue def initialize - # @store = ... - raise NotImplementedError, "Not yet implemented" + @store = Array.new(QUEUE_SIZE) + @front = @rear = -1 end - def enqueue(element) - raise NotImplementedError, "Not yet implemented" + def enqueue(element) # add to rear + if @front == -1 # Queue is empty + @rear = 1 + @front = 0 + @store[@front] = element + elsif @front == @rear + raise Error, "Queue full" + else + new_rear = (@rear + 1) % QUEUE_SIZE + @store[@rear] = element + @rear = new_rear + end + return @store end - def dequeue - raise NotImplementedError, "Not yet implemented" + def dequeue # remove from front + removed = @store[@front] + @store[@front] = nil + self.size == 0 ? @front = -1 : @front += 1 + return removed end def front - raise NotImplementedError, "Not yet implemented" + return @store[@front] end def size - raise NotImplementedError, "Not yet implemented" + size = 0 + @store.each do |val| + if !val.nil? + size += 1 + end + end + return size end def empty? - raise NotImplementedError, "Not yet implemented" + return true if self.size == 0 + return false end - def to_s - return @store.to_s + def to_string + formatted_array = [] + @store.each do |x| + if !x.nil? + formatted_array << x + end + end + return formatted_array.to_s end -end +end \ No newline at end of file diff --git a/lib/stack.rb b/lib/stack.rb index cfc6ef0f..b720897b 100644 --- a/lib/stack.rb +++ b/lib/stack.rb @@ -1,19 +1,24 @@ +require_relative './linked_list' + class Stack def initialize - # @store = ... - raise NotImplementedError, "Not yet implemented" + @store = LinkedList.new() end - def push(element) - raise NotImplementedError, "Not yet implemented" + def push(element) # add to end + @store.add_last(element) end - def pop - raise NotImplementedError, "Not yet implemented" + def pop # remove from end + @store.remove_last if !self.empty? end def empty? - raise NotImplementedError, "Not yet implemented" + @store.empty? + end + + def peak_last + return @store.get_last end def to_s diff --git a/test/problems_test.rb b/test/problems_test.rb index 9d30e1cd..93339628 100644 --- a/test/problems_test.rb +++ b/test/problems_test.rb @@ -7,24 +7,24 @@ describe "Test wave 3 problems" do describe "balanced" do it "Given balanced strings it should return true" do - skip + # skip expect(balanced('(({}))')).must_equal true end it "regards an empty string as balanced" do - skip + # skip expect(balanced('')).must_equal true end it "will return false for an unbalanced set of parens" do - skip + # skip expect(balanced('(()')).must_equal false expect(balanced('(()}')).must_equal false expect(balanced('([]]')).must_equal false end it "also works for {} and []" do - skip + # skip expect(balanced('[]')).must_equal true expect(balanced('{}')).must_equal true end diff --git a/test/queue_test.rb b/test/queue_test.rb index 9b616a30..05935cc3 100644 --- a/test/queue_test.rb +++ b/test/queue_test.rb @@ -11,29 +11,28 @@ end it "adds something to an empty Queue" do - skip q = Queue.new q.enqueue(10) - q.to_s.must_equal "[10]" + q.to_string.must_equal "[10]" end it "adds multiple somethings to a Queue" do - skip + # skip q = Queue.new q.enqueue(10) q.enqueue(20) q.enqueue(30) - q.to_s.must_equal "[10, 20, 30]" + q.to_string.must_equal "[10, 20, 30]" end it "starts the size of a Queue at 0" do - skip + # skip q = Queue.new q.empty?.must_equal true end it "removes something from the Queue" do - skip + # skip q = Queue.new q.enqueue(5) removed = q.dequeue @@ -42,18 +41,18 @@ end it "removes the right something (LIFO)" do - skip + # skip q = Queue.new q.enqueue(5) q.enqueue(3) q.enqueue(7) removed = q.dequeue removed.must_equal 5 - q.to_s.must_equal "[3, 7]" + q.to_string.must_equal "[3, 7]" end it "properly adjusts the size with enqueueing and dequeueing" do - skip + # skip q = Queue.new q.empty?.must_equal true q.enqueue(-1) @@ -65,7 +64,7 @@ end it "returns the front element in the Queue" do - skip + # skip q = Queue.new q.enqueue(40) q.enqueue(22) diff --git a/test/stack_test.rb b/test/stack_test.rb index df5046c8..4c9118ac 100644 --- a/test/stack_test.rb +++ b/test/stack_test.rb @@ -10,14 +10,14 @@ end it "pushes something onto a empty Stack" do - skip + # skip s = Stack.new s.push(10) s.to_s.must_equal "[10]" end it "pushes multiple somethings onto a Stack" do - skip + # skip s = Stack.new s.push(10) s.push(20) @@ -26,13 +26,13 @@ end it "starts the stack empty" do - skip + # skip s = Stack.new s.empty?.must_equal true end it "removes something from the stack" do - skip + # skip s = Stack.new s.push(5) removed = s.pop @@ -41,7 +41,7 @@ end it "removes the right something (LIFO)" do - skip + # skip s = Stack.new s.push(5) s.push(3)