Problem statement

https://binarysearch.com/problems/Arithmetic-Sequence-Permutation/

Solution

Sort numbers and then check that all differences between adjacent elements are equal.

Complexity

It is O(n log n) for time and O(n) for space.

Code

class Solution:
    def solve(self, nums):
        nums = sorted(nums)
        return len(set(y - x for x, y in zip(nums, nums[1:]))) == 1

Remark

There is also O(n) time complexity solution: find the smallest and the biggest values, create candidate for sequence and then check equality of counters.