res = []

        nums.sort()

        if len(nums)<3:return []

        for i in range(len(nums)-2):

            left = i+1

            right = len(nums)-1

            while left < right:

                val = nums[i]+nums[left]+nums[right]

                if val==0 and [nums[i],nums[left],nums[right]] not in res:

                    res.append([nums[i],nums[left],nums[right]])

                elif val<0:

                    left += 1

                else:

                    right -=1

        return res

nums.sort()

        res = []

        for i in range(len(nums) - 2):

            if i > 0 and nums[i-1] == nums[i]: continue

            l, r = i + 1, len(nums) - 1

            while l < r:

                s = nums[i] + nums[l] + nums[r]

                if s == 0:

                    res.append([nums[i], nums[l], nums[r]])

                    l += 1; r -= 1

                    while l < r and nums[l] == nums[l-1]: l += 1

                    while l < r and nums[r] == nums[r+1] : r -= 1

                elif s < 0:

                    l += 1

                else:

                   r -= 1

        return res