def three_sum(nums):
    values = sorted(nums)
    output = []
    for i in range(len(values) - 2):
        if i and values[i] == values[i - 1]:
            continue
        left, right = i + 1, len(values) - 1
        while left < right:
            total = values[i] + values[left] + values[right]
            if total == 0:
                output.append([values[i], values[left], values[right]])
                left += 1
                right -= 1
                while left < right and values[left] == values[left - 1]:
                    left += 1
                while left < right and values[right] == values[right + 1]:
                    right -= 1
            elif total < 0:
                left += 1
            else:
                right -= 1
    return output