2799. Count Complete Subarrays in an Array - LeetCode

class Solution:
    def countCompleteSubarrays(self, nums: list[int]) -> int:
        amt, D, result, i = {}, len(set(nums)), 0, 0
        for num in nums:
            amt[num] = amt.get(num, 0) + 1
            while len(amt) == D:
                amt[nums[i]] -= 1
                if amt[nums[i]] == 0:
                    del amt[nums[i]]
                i += 1
            result += i
        return result