选择排序
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def selection_sort(collection: list[int]) -> list[int]:
"""
Sorts a list in ascending order using the selection sort algorithm.
:param collection: A list of integers to be sorted.
:return: The sorted list.
Examples:
>>> selection_sort([0, 5, 3, 2, 2])
[0, 2, 2, 3, 5]
>>> selection_sort([])
[]
>>> selection_sort([-2, -5, -45])
[-45, -5, -2]
"""
length = len(collection)
for i in range(length - 1):
min_index = i
for k in range(i + 1, length):
if collection[k] < collection[min_index]:
min_index = k
if min_index != i:
collection[i], collection[min_index] = collection[min_index], collection[i]
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(",")]
sorted_list = selection_sort(unsorted)
print("Sorted List:", sorted_list)
关于此算法
问题陈述
给定一个包含 n 个元素的无序数组，编写一个函数对数组进行排序。
方法
- 从数组中选择最小的元素。
- 将其放在数组的开头。
- 然后从剩余的未排序列表中选择最小的元素。
- 将其追加到排序数组的开头。
- 对数组的每个元素重复此操作。
- 重复上述过程 n 次。
时间复杂度
O(n^2) 最坏情况下的性能
O(n^2) 最佳情况下的性能
O(n^2) 平均性能
空间复杂度
O(1) 最坏情况
示例
arr[] = {80, 10, 40, 30}
Indexes: 0 1 2 3
1. Index = 0
Select the minimum number from the array (between index 0-3), ie, 10
2. Swap 10 and 80 (arr[0])
3. The array now is {10, 80, 40, 30}
4. Index = 1
Select the minimum number from the array (between index 1-3), ie, 30
5. Swap 30 and 80 (arr[1])
6. The array now is {10, 30, 40, 80}
7. Index = 2
Select the minimum number from the array (between index 2-3), ie, 40
8. Swap 40 and 40 (arr[2])
9. The array now is {10, 30, 40, 80}
The array is now sorted.
