2025-08-21 11:42:42 +0000 UTC

class Solution:
    def distinctDifferenceArray(self, nums: List[int]) -> List[int]:
        left, right = set(), defaultdict(int)
        for num in nums:
            right[num] += 1
        res = []
        for num in nums:
            left.add(num)
            right[num] -= 1
            if right[num] == 0:
                del right[num]
            res.append(len(left) - len(right))
        return res