Python程序，用于检查枢轴左侧和右侧的元素是否分别较小或较大

给定一个列表和一个索引，任务是编写一个Python程序，首先选择该索引处的元素作为枢轴元素，然后测试元素是否在其右侧较大而左侧较小。

例子：

Input : test_list = [4, 3, 5, 6, 9, 16, 11, 10, 12], K = 4

Output : True

Explanation : Elements at Kth index is 9, elements before that are smaller and next are greater.

Input : test_list = [4, 3, 5, 6, 9, 16, 11, 10, 1], K = 4

Output : False

Explanation : Elements at Kth index is 9, elements before that are smaller but 1 is after 4th index, less than 9.

方法 1：使用循环和enumerate()

在这里，我们使用循环遍历元素，枚举用于获取索引并检查索引是否大于或小于 K，以切换测试条件。

程序：

Python3

# initializing list
test_list = [4, 3, 5, 6, 9, 16, 11, 10, 12]
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K
K = 4
  
res = True
for idx, ele in enumerate(test_list):
  
    # checking for required conditions
    if (idx > K and ele < test_list[K]) or (idx < K and ele > test_list[K]):
        res = False
  
# printing result
print("Is condition met ? : " + str(res))

输出：

The original list is : [4, 3, 5, 6, 9, 16, 11, 10, 12]

Is condition met ? : True

方法 2：使用all()和enumerate()

使用 all() 执行类似的任务，它可以使用单行生成器表达式测试所需的条件，以提供更紧凑的解决方案。

程序：

蟒蛇3

# initializing list
test_list = [4, 3, 5, 6, 9, 16, 11, 10, 12]
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing K
K = 4
  
# all() used to check for condition using one liner
res = all(not ((idx > K and ele < test_list[K]) or (
    idx < K and ele > test_list[K])) for idx, ele in enumerate(test_list))
  
# printing result
print("Is condition met ? : " + str(res))

输出：

The original list is : [4, 3, 5, 6, 9, 16, 11, 10, 12]

Is condition met ? : True