reorganize dir

Signed-off-by: Mia Steinkirch <mia.steinkirch@gmail.com>

ebook_src/abstract_structures/heap/heapify.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+class Heapify(object):
+    def __init__(self, data=None):
+        self.data = data or []
+        for i in range(len(data)//2, -1, -1):
+            self.__max_heapify__(i)
+
+    def __repr__(self):
+        return '{}'.format(self.data)
+
+    def parent(self, i):
+        return i >> 1
+
+    def left_child(self, i):
+        return (i << 1) + 1
+
+    def right_child(self, i):
+        return (i << 1) + 2 # +2 instead of +1 because it's 0-indexed.
+
+    def __max_heapify__(self, i):
+        largest = i
+        left = self.left_child(i)
+        right = self.right_child(i)
+        n = len(self.data)
+        largest = (left < n and self.data[left] > self.data[i]) and left or i
+        largest = (right < n and self.data[right] > self.data[largest]) and right or largest
+        if i is not largest:
+            self.data[i], self.data[largest] = self.data[largest], self.data[i]
+            self.__max_heapify__(largest)
+
+    def extract_max(self):
+        n = len(self.data)
+        max_element = self.data[0]
+        self.data[0] = self.data[n - 1]
+        self.data = self.data[:n - 1]
+        self.__max_heapify__(0)
+        return max_element
+
+
+def test_Heapify():
+    l1 = [3, 2, 5, 1, 7, 8, 2]
+    h = Heapify(l1)
+    assert(h.extract_max() == 8)
+
+if __name__ == '__main__':
+    test_Heapify()