Create Heap Sort.py

Python/Heap Sort.py

@@ -0,0 +1,46 @@
+# Python program for implementation of heap Sort 
+
+# To heapify subtree rooted at index i. 
+# n is size of heap 
+def heapify(arr, n, i): 
+    largest = i # Initialize largest as root 
+    l = 2 * i + 1     # left = 2*i + 1 
+    r = 2 * i + 2     # right = 2*i + 2 
+
+    # See if left child of root exists and is 
+    # greater than root 
+    if l < n and arr[i] < arr[l]: 
+        largest = l 
+
+    # See if right child of root exists and is 
+    # greater than root 
+    if r < n and arr[largest] < arr[r]: 
+        largest = r 
+
+    # Change root, if needed 
+    if largest != i: 
+        arr[i],arr[largest] = arr[largest],arr[i] # swap 
+
+        # Heapify the root. 
+        heapify(arr, n, largest) 
+
+# The main function to sort an array of given size 
+def heapSort(arr): 
+    n = len(arr) 
+
+    # Build a maxheap. 
+    for i in range(n//2 - 1, -1, -1): 
+        heapify(arr, n, i) 
+
+    # One by one extract elements 
+    for i in range(n-1, 0, -1): 
+        arr[i], arr[0] = arr[0], arr[i] # swap 
+        heapify(arr, i, 0) 
+
+# Driver code to test above 
+arr = [ 12, 11, 13, 5, 6, 7] 
+heapSort(arr) 
+n = len(arr) 
+print ("Sorted array is") 
+for i in range(n): 
+    print ("%d" %arr[i]),