heap_sort.py

""" created by Sarvesh kumar sharma """

'''implementation of the Heap sort algorithm in Python'''


# heap sort
def heap_sort(list2):
    first = 0
    last = len(list2) - 1
    create_heap(list2, first, last)
    for i in range(last, first, -1):
        list2[i], list2[first] = list2[first], list2[i]  # swap
        establish_heap_property(list2, first, i - 1)


# create heap (used by heap_sort)
def create_heap(list2, first, last):
    i = last / 2
    while i >= first:
        establish_heap_property(list2, i, last)
        i -= 1


# establish heap property (used by create_heap)
def establish_heap_property(list2, first, last):
    while 2 * first + 1 <= last:
        k = 2 * first + 1
        if k < last and list2[k] < list2[k + 1]:
            k += 1
        if list2[first] >= list2[k]:
            break
        list2[first], list2[k] = list2[k], list2[first]  # swap
        first = k


if __name__ == "__main__":
    user_input = input("Enter numbers separated by a comma:\n").strip()
    unsorted = [int(item) for item in user_input.split(",")]
    print(heap_sort(unsorted))