HeapSort.py

# Python program for implementation of heap Sort


def heapify(arr, n, i):
    largest = i
    l = 2 * i + 1
    r = 2 * i + 2

    if l < n and arr[i] < arr[l]:
        largest = l

    if r < n and arr[largest] < arr[r]:
        largest = r

    if largest != i:
        arr[i], arr[largest] = arr[largest], arr[i]

        heapify(arr, n, largest)


def heapSort(arr):
    n = len(arr)

    for i in range(n // 2 - 1, -1, -1):
        heapify(arr, n, i)

    for i in range(n-1, 0, -1):
        arr[i], arr[0] = arr[0], arr[i]
        heapify(arr, i, 0)


# Program starts
arr = [3, 15, 22, 8, 19, 7]
heapSort(arr)
n = len(arr)
print("Sorted array is")
for i in range(n):
    print("%d" % arr[i]),