1 files changed, 11 insertions, 0 deletions
diff --git a/algorithms/impl/heapsort.py b/algorithms/impl/heapsort.py
index bf9f464..81bea20 100644
--- a/algorithms/impl/heapsort.py
+++ b/algorithms/impl/heapsort.py
@@ -9,6 +9,7 @@ from ..algorithm import SortingAlgorithm
 
 # Disclaimer: implemented in the most literate way.
 
+
 def heapsort(xs):
     _heapify(xs)
     first, last = 0, len(xs) - 1
@@ -17,26 +18,32 @@ def heapsort(xs):
         _siftdown(xs, first, end - 1)
     return xs
 
+
 # In a heap stored in a zero-based array,
 # left_child = node * 2 + 1
 # right_child = node * 2 + 2
 # parent = (node - 1) // 2
 
+
 def _get_parent(node):
     return (node - 1) // 2
 
+
 def _get_left_child(node):
     return node * 2 + 1
 
+
 def _get_right_child(node):
     return node * 2 + 2
 
+
 def _heapify(xs):
     last = len(xs) - 1
     first_parent, last_parent = 0, _get_parent(last)
     for parent in range(last_parent, first_parent - 1, -1):
         _siftdown(xs, parent, last)
 
+
 def _siftdown(xs, start, end):
     root = start
     while True:
@@ -54,18 +61,22 @@ def _siftdown(xs, start, end):
         else:
             break
 
+
 _ALGORITHMS = [
     SortingAlgorithm('heapsort', 'Heapsort', heapsort),
 ]
 
+
 def _parse_args(args=None):
     if args is None:
         args = sys.argv[1:]
     return list(map(int, args))
 
+
 def main(args=None):
     xs = _parse_args(args)
     print(heapsort(list(xs)))
 
+
 if __name__ == '__main__':
     main()