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# Runtime: 549 ms (Top 98.6%) | Memory: 23.43 MB (Top 9.7%)
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class Solution:
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    def countTriplets(self, nums: List[int]) -> int:
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        freq = defaultdict(int)
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        for x in nums:
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            for y in nums:
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                freq[x & y] += 1
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        ans = 0
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        for x in nums:
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            mask = x = x ^ 0xFFFF
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            while x:
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                ans += freq[x]
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                x = mask & (x - 1)
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            ans += freq[0]
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        return ans