mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-10-06 05:39:30 +00:00
59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
from __future__ import annotations
|
|
|
|
|
|
# Divide and Conquer algorithm
|
|
def find_min(nums: list[int | float], left: int, right: int) -> int | float:
|
|
"""
|
|
find min value in list
|
|
:param nums: contains elements
|
|
:param left: index of first element
|
|
:param right: index of last element
|
|
:return: min in nums
|
|
|
|
>>> for nums in ([3, 2, 1], [-3, -2, -1], [3, -3, 0], [3.0, 3.1, 2.9]):
|
|
... find_min(nums, 0, len(nums) - 1) == min(nums)
|
|
True
|
|
True
|
|
True
|
|
True
|
|
>>> nums = [1, 3, 5, 7, 9, 2, 4, 6, 8, 10]
|
|
>>> find_min(nums, 0, len(nums) - 1) == min(nums)
|
|
True
|
|
>>> find_min([], 0, 0)
|
|
Traceback (most recent call last):
|
|
...
|
|
ValueError: find_min() arg is an empty sequence
|
|
>>> find_min(nums, 0, len(nums)) == min(nums)
|
|
Traceback (most recent call last):
|
|
...
|
|
IndexError: list index out of range
|
|
>>> find_min(nums, -len(nums), -1) == min(nums)
|
|
True
|
|
>>> find_min(nums, -len(nums) - 1, -1) == min(nums)
|
|
Traceback (most recent call last):
|
|
...
|
|
IndexError: list index out of range
|
|
"""
|
|
if len(nums) == 0:
|
|
raise ValueError("find_min() arg is an empty sequence")
|
|
if (
|
|
left >= len(nums)
|
|
or left < -len(nums)
|
|
or right >= len(nums)
|
|
or right < -len(nums)
|
|
):
|
|
raise IndexError("list index out of range")
|
|
if left == right:
|
|
return nums[left]
|
|
mid = (left + right) >> 1 # the middle
|
|
left_min = find_min(nums, left, mid) # find min in range[left, mid]
|
|
right_min = find_min(nums, mid + 1, right) # find min in range[mid + 1, right]
|
|
|
|
return left_min if left_min <= right_min else right_min
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import doctest
|
|
|
|
doctest.testmod(verbose=True)
|