python面试题（二）顺时针打印二维数组，快速排序

 1 def output_array(matrix):
 2     ‘‘‘
 3     输入一个矩阵，返回一个顺时针打印的列表
 4     :param matrix: 矩阵（二维数组）
 5     :return: list
 6     ‘‘‘
 7     list = []
 8     while True:
 9         try:
10             # 顺序打印矩阵第一行
11             len_top = len(matrix[0])
12             for i in range(len_top):
13                 list.append(matrix[0].pop(0))
14             matrix.pop(0)   # ①第一行的元素已经pop完了，但是此时matrix[0] = []而非none，所以这里得pop一下
15 
16             # 依次打印最右边的一列（每一行的最后一个元素）
17             len_right = len(matrix)
18             for j in range(len_right):
19                 list.append(matrix[j].pop(-1))
20 
21             # 倒序打印最下面一行
22             len_bottom = len(matrix[0])
23             for k in range(len_bottom):
24                 list.append(matrix[-1].pop(-1))
25             matrix.pop(-1)  # 同①
26 
27             # 倒序打印最左边的一行（倒序打印每一行的第一个元素）
28             len_left = len(matrix)
29             for l in range(len_left):
30                 list.append(matrix[-l-1].pop(0))
31 
32         except BaseException:   # 这是个比较懒的方法，没有设置跳出条件，只有触发list out of range 来跳出循环
33             return list
34 
35 # --------测试用例------------------
36 if __name__ == ‘__main__‘:
37     a = [[1,2,3],[4,5,6],[7,8,9],[10,11,12],[13,14,15],[16,17,18]]  # 小奇数*大偶数
38     b = [[1,2,3,4,5,6],[7,8,9,10,11,12],[13,14,15,16,17,18]]        # 大奇数*小偶数
39     c = [[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]]            # 偶数*偶数
40     d = [[1,2,3],[4,5,6],[7,8,9]]                                   # 奇数*奇数
41     e = [[1,2],[3,4],[5,6]]                                         # 小偶数*大奇数
42     f = [[1,2,3,4]]                                                 # 大偶数*小奇数
43     for i in [a,b,c,d,e,f]:
44         print(output_array(i))

1 /Users/***/anaconda3/bin/python /Users/***/Documents/project/0911/面试/牛客编程/顺时针打印矩阵.py
2 [1, 2, 3, 6, 9, 12, 15, 18, 17, 16, 13, 10, 7, 4, 5, 8, 11, 14]
3 [1, 2, 3, 4, 5, 6, 12, 18, 17, 16, 15, 14, 13, 7, 8, 9, 10, 11]
4 [1, 2, 3, 4, 8, 12, 16, 15, 14, 13, 9, 5, 6, 7, 11, 10]
5 [1, 2, 3, 6, 9, 8, 7, 4, 5]
6 [1, 2, 4, 6, 5, 3]
7 [1, 2, 3, 4]
9 Process finished with exit code 0

 1 #-*- coding:utf-8 -*-
 2 #Author: Bing Xu
 3 
 4 def quick_sort(list,start,end):
 5 
 6     if start >= end:
 7         return list
 8 
 9     low = start
10     high = end
11     mid = list[start]
12 
13     while low < high:
14         while low < high and list[high] >= mid:
15             high -= 1
16         list[low] = list[high]
17         while low < high and list[low] < mid:
18             low += 1
19         list[high] = list[low]
20         list[low] = mid
21     quick_sort(list,start,low-1)
22     quick_sort(list,low+1,end)
23     return list
24 
25 #------------- 测试 ---------------
26 if __name__ == ‘__main__‘:
27     a = [1,2,6,5,3]
28     b = []
29     # c = [-1,1,3,‘l‘]
30     # e = [1+2j,1,2]　　暂不支持比较字符和复数，明天再想办法解决
31     for i in [a,b]:
32         print(quick_sort(i,0,len(i)-1))

1 [1, 2, 3, 5, 6]
2 []
3 
4 Process finished with exit code 0