1. 冒泡排序(Bubble Sort)
冒泡排序是一种简单的排序算法,通过重复地遍历列表,比较相邻的元素并交换它们,直到整个列表有序。
def bubble_sort(arr):
n = len(arr)
for i in range(n):
for j in range(0, n-i-1):
if arr[j] > arr[j+1]:
arr[j], arr[j+1] = arr[j+1], arr[j]
my_list = [64, 34, 25, 12, 22, 11, 90]
bubble_sort(my_list)
print("Sorted array is:", my_list)
2. 快速排序(Quick Sort)
快速排序是一种分治排序算法,通过选择一个“枢纽”元素,将列表分割为两部分,再递归地排序每一部分。
def quick_sort(arr):
if len(arr) <= 1:
return arr
pivot = arr[len(arr) // 2]
left = [x for x in arr if x < pivot]
middle = [x for x in arr if x == pivot]
right = [x for x in arr if x > pivot]
return quick_sort(left) + middle + quick_sort(right)
my_list = [3, 6, 8, 10, 1, 2, 1]
sorted_list = quick_sort(my_list)
print("Sorted array is:", sorted_list)
3. 插入排序(Insertion Sort)
插入排序通过构建有序序列,对于未排序数据,在已排序序列中从后向前扫描,找到相应位置并插入。
def insertion_sort(arr):
for i in range(1, len(arr)):
key = arr[i]
j = i - 1
while j >= 0 and key < arr[j]:
arr[j + 1] = arr[j]
j -= 1
arr[j + 1] = key
my_list = [12, 11, 13, 5, 6]
insertion_sort(my_list)
print("Sorted array is:", my_list)
4. 选择排序(Selection Sort)
选择排序通过反复地从未排序部分选择最小(或最大)元素,将其移到已排序部分的末尾。
def selection_sort(arr):
for i in range(len(arr)):
min_idx = i
for j in range(i+1, len(arr)):
if arr[j] < arr[min_idx]:
min_idx = j
arr[i], arr[min_idx] = arr[min_idx], arr[i]
my_list = [64, 25, 12, 22, 11]
selection_sort(my_list)
print("Sorted array is:", my_list)
5. 归并排序(Merge Sort)
归并排序是一种分治算法,将列表分成若干子列表,分别排序后再合并。
def merge_sort(arr):
if len(arr) <= 1:
return arr
mid = len(arr) // 2
left = merge_sort(arr[:mid])
right = merge_sort(arr[mid:])
return merge(left, right)
def merge(left, right):
result = []
i = j = 0
while i < len(left) and j < len(right):
if left[i] < right[j]:
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
result.extend(left[i:])
result.extend(right[j:])
return result
my_list = [38, 27, 43, 3, 9, 82, 10]
sorted_list = merge_sort(my_list)
print("Sorted array is:", sorted_list)