在列表中查找第一最大值的索引，将其编译为python中的值

Question

I have a sorted list

my_list = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384]

I have a value lets say 445. I want to find the index of first max in list. For above case, it should return index value 9 (512).

Answer 1

The easiest way is to use binary search to find the required index, because the input list is sorted. This algorithm is already implemented in the bisect module:

import bisect

my_list = [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384]
print(bisect.bisect_right(my_list, 445))
print(bisect.bisect_right(my_list, 512))

Prints:

9
10