insertion sort Algorithm
Insertion sort is a simple sorting algorithm that builds the final sorted array (or list) one item at a time.
However, insertion sort provides several advantages:
Simple implementation: Jon Bentley shows a three-line c version, and a five-line optimized version
Efficient for (quite) small data sets, much like other quadratic sorting algorithmsAdaptive, i.e., efficient for data sets that are already substantially sorted: the time complexity is O(kn) when each component in the input is no more than K places away from its sorted position
Stable; i.e., makes not change the relative order of components with equal keys
"""
This is a pure Python implementation of the insertion sort algorithm
For doctests run following command:
python -m doctest -v insertion_sort.py
or
python3 -m doctest -v insertion_sort.py
For manual testing run:
python insertion_sort.py
"""
def insertion_sort(collection):
"""Pure implementation of the insertion sort algorithm in Python
:param collection: some mutable ordered collection with heterogeneous
comparable items inside
:return: the same collection ordered by ascending
Examples:
>>> insertion_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> insertion_sort([])
[]
>>> insertion_sort([-2, -5, -45])
[-45, -5, -2]
"""
for loop_index in range(1, len(collection)):
insertion_index = loop_index
while (
insertion_index > 0
and collection[insertion_index - 1] > collection[insertion_index]
):
collection[insertion_index], collection[insertion_index - 1] = (
collection[insertion_index - 1],
collection[insertion_index],
)
insertion_index -= 1
return collection
if __name__ == "__main__":
user_input = input("Enter numbers separated by a comma:\n").strip()
unsorted = [int(item) for item in user_input.split(",")]
print(insertion_sort(unsorted))
