python面试：实现快速排序（python经典编程案例）

import random
import timeit


def randomList(n):
    '''返回一个长度为n的整数列表，数据范围[0,1000) '''
    iList = []
    for i in range(n):
        iList.append(random.randrange(1000))
    return iList


def quickSort(iList):
    if len(iList) <= 1:
        return iList
    left = []
    right = []
    for i in iList[1:]:
        if i <= iList[0]:
            left.append(i)
        else:
            right.append(i)
    return quickSort(left) + [iList[0]] + quickSort(right)


if __name__ == "__main__":
    iList = randomList(20)
    print(iList)
    print(quickSort(iList))
    print(timeit.timeit("quickSort(iList)", "from __main__ import quickSort,iList", number=100))

执行结果如下：

[570, 881, 704, 70, 871, 423, 583, 411, 856, 999, 220, 991, 877, 301, 795, 290, 95, 13, 289, 419]
[13, 70, 95, 220, 289, 290, 301, 411, 419, 423, 570, 583, 704, 795, 856, 871, 877, 881, 991, 999]
0.0019199240000000034