在Python3.x中某些情况下获取超时错误

我正在处理欺诈活动通知问题: https://www.hackerrank.com/challenges/fraudulent-activity-notifications/ 解决这个问题。这段代码在某些测试用例中运行良好,但在某些测试用例中失败,导致超时错误。有谁能帮助我了解如何优化

def calculate_median(lists):    
    n = len(lists)
    lists.sort()
    if n % 2 == 0: 
        median1 = lists[n//2] 
        median2 = lists[n//2 - 1] 
        median = (median1 + median2)/2
    else: 
        median = lists[n//2] 
    return median


my_list = [2,3,4,2,3,6,8,4,5]
d=5
n = len(my_list)
count = 0
start= 0
end = d
for i in range(0, len(my_list)):
    if end < n:
        seg_list = my_list[start:end]
        check_val = my_list[end]
        median_val = calculate_median(seg_list)
        if check_val >= 2 *median_val:
            count = count +1 
        start = start + 1
        end = end + 1

print(count)