冒泡排序

# 冒泡排序，默认升序
def bubbleSort(arr, order=True):
    n = len(arr)
    for i in range(n):
        for j in range(n - 1 - i):
            # 如果是升序
            if order:
                if arr[j] > arr[j + 1]:
                    arr[j], arr[j + 1] = arr[j + 1], arr[j]
            # 如果是降序
            else:
                if arr[j] < arr[j + 1]:
                    arr[j], arr[j + 1] = arr[j + 1], arr[j]
    return arr


if __name__ == '__main__':
    arr = [2, 3, 1, 5, 6, 4, 8, 7, 9]
    print(bubbleSort(arr, order=False))