Python/sorts/pancake_sort.py
2019-10-05 10:14:13 +05:00

40 lines
1.1 KiB
Python

"""
This is a pure python implementation of the pancake sort algorithm
For doctests run following command:
python3 -m doctest -v pancake_sort.py
or
python -m doctest -v pancake_sort.py
For manual testing run:
python pancake_sort.py
"""
def pancake_sort(arr):
"""Sort Array with Pancake Sort.
:param arr: Collection containing comparable items
:return: Collection ordered in ascending order of items
Examples:
>>> pancake_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> pancake_sort([])
[]
>>> pancake_sort([-2, -5, -45])
[-45, -5, -2]
"""
cur = len(arr)
while cur > 1:
# Find the maximum number in arr
mi = arr.index(max(arr[0:cur]))
# Reverse from 0 to mi
arr = arr[mi::-1] + arr[mi + 1 : len(arr)]
# Reverse whole list
arr = arr[cur - 1 :: -1] + arr[cur : len(arr)]
cur -= 1
return arr
if __name__ == "__main__":
user_input = input("Enter numbers separated by a comma:\n").strip()
unsorted = [int(item) for item in user_input.split(",")]
print(pancake_sort(unsorted))