Earth | Ana

lib/heap_sort.rb

@@ -4,5 +4,16 @@
 # Time Complexity:  ?
 # Space Complexity: ?
 def heap_sort(list)
-  raise NotImplementedError, "Method not implemented yet..."
+  heap = MinHeap.new
+
+  list.each do |i|
+    heap.add(i)
+  end
+
+  sorted_array = []
+
+  until heap.empty?
+    sorted_array << heap.remove
+  end
+    return sorted_array
 end

lib/min_heap.rb

@@ -17,15 +17,24 @@ def initialize
   # Time Complexity: ?
   # Space Complexity: ?
   def add(key, value = key)
-    raise NotImplementedError, "Method not implemented yet..."
+    @store << HeapNode.new(key, value)
+    return heap_up(@store.length - 1)
   end
 
   # This method removes and returns an element from the heap
   #   maintaining the heap structure
   # Time Complexity: ?
   # Space Complexity: ?
   def remove()
-    raise NotImplementedError, "Method not implemented yet..."
+    return nil if @store.empty?
+
+
+    removed = @store[0]
+    swap(0, @store.length - 1)
+    @store = @store[0...-1]
+
+    heap_down(0)
+    return removed.value
   end
 
 
@@ -47,7 +56,7 @@ def to_s
   # Time complexity: ?
   # Space complexity: ?
   def empty?
-    raise NotImplementedError, "Method not implemented yet..."
+    return @store.length == 0
   end
 
   private
@@ -58,7 +67,12 @@ def empty?
   # Time complexity: ?
   # Space complexity: ?
   def heap_up(index)
-
+    return nil if index == 0
+    parent = (index -1 ) / 2
+    if @store[index].key < @store[parent].key
+      swap(index, parent)
+      heap_up(parent)
+    end
   end
 
   # This helper method takes an index and