如何根据最后两位数字对数字列表进行排序？

Question

Is it possible? I have to sort it without the sort functions but I want to see if I can sort it based on the last two digits.

Answer 1

You can use the built in list.sort method or sorted function with a key function. The function lambda n: abs(n) % 100 gets the last two digits:

>>> nums = [99, 888, 7777, 66666, 555555]
>>> sorted(nums, key=lambda n: abs(n) % 100)
[555555, 66666, 7777, 888, 99]

The abs makes it work for negative numbers as well. If your list has no negative numbers, you can just write n % 100 .

If you are sorting using your own algorithm, one way is to follow the " decorate, sort, undecorate " pattern: build a list of pairs where the first component is the sort key, then write your sorting algorithm as normal, then extract the original values to return the sorted list.

def sort_by_last_two_digits(nums):
    nums = [(abs(n) % 100, n) for n in nums]

    # do the sorting normally

    return [n for _, n in nums]