线性查找
# -*- coding: utf-8 -*-
# Author: 桑葚ICE
# Email: 152516cc@gmail.com
# Blog: iicey.github.io
# JueJin: juejin.im/user/5c64dce8e51d45013c40742c
def search(arr, x):
for i in range(len(arr)):
if arr[i] == x:
return i
return -1
if __name__ == '__main__':
print(search(['A', 'B', 'C', 'D', 'E'], 'D'))
冒泡排序
# -*- coding: utf-8 -*-
# Author: 桑葚ICE
# Email: 152516cc@gmail.com
# Blog: iicey.github.io
# JueJin: juejin.im/user/5c64dce8e51d45013c40742c
def bubble_sort(arr):
n = len(arr)
# 遍历所有数组元素
for i in range(n):
# Last i elements are already in place
for j in range(0, n - i - 1):
if arr[j] > arr[j + 1]:
arr[j], arr[j + 1] = arr[j + 1], arr[j]
print(i, j, arr)
return arr
if __name__ == '__main__':
print(bubble_sort([64, 34, 25, 12, 22, 11, 90]))
插入排序
# -*- coding: utf-8 -*-
# Author: 桑葚ICE
# Email: 152516cc@gmail.com
# Blog: iicey.github.io
# JueJin: juejin.im/user/5c64dce8e51d45013c40742c
def insertion_sort(arr):
for i in range(1, len(arr)): # 默认第一个元素已经在有序序列中,从后面元素开始插入
for j in range(i, 0, -1): # 逆向遍历比较,交换位置实现插入
if arr[j] < arr[j - 1]:
arr[j], arr[j - 1] = arr[j - 1], arr[j]
print(i, j, arr)
return arr
if __name__ == '__main__':
print(insertion_sort([23, 51, 436, 32, 54, 76, 6, 87, 789, 53, 6543, 5]))
堆排序
# -*- coding: utf-8 -*-
# Author: 桑葚ICE
# Email: 152516cc@gmail.com
# Blog: iicey.github.io
# JueJin: juejin.im/user/5c64dce8e51d45013c40742c
def heapify(arr, n, i):
largest = i # 父节点
left = 2 * i + 1 # 左节点
right = 2 * i + 2 # 右节点
if left < n and arr[i] < arr[left]:
largest = left
if right < n and arr[largest] < arr[right]:
largest = right
if largest != i:
arr[i], arr[largest] = arr[largest], arr[i] # 交换
heapify(arr, n, largest)
print(f"n:{n}, i:{i}, largest:{largest}, left:{left}, right:{right}, arr:{arr}")
def heap_sort(arr):
n = len(arr)
for i in range(n, -1, -1):
heapify(arr, n, i)
# 一个个交换元素
print('***********************')
for i in range(n - 1, 0, -1):
arr[i], arr[0] = arr[0], arr[i]
print(arr)
heapify(arr, i, 0)
return arr
if __name__ == '__main__':
print(heap_sort([2, 4, 3, 6, 5, 8, 7]))