9-冒泡排序-性能改进

# 通过监测每趟比对是否发生过交换，可以提前确定排序是否完成
# 如果某趟比对没有发生任何交换，说明列表已经排好序，可以提前结束算法


def shortBubbleSort(alist):
    exchanges = True
    passnum = len(alist) - 1
    while passnum > 0 and exchanges:
        exchanges = False
        for i in range(passnum):
            if alist[i] > alist[i+1]:
                exchanges = True
                alist[i], alist[i+1] = alist[i+1], alist[i]
        passnum -= 1


testlist = [2, 3, 3, 243, 24, 24455, 23]
shortBubbleSort(testlist)
print(testlist)