Three Summedium

def three_sum(nums: list[int]) -> list[list[int]]:
    # TODO: find all unique triplets that sum to zero
    # Hint: sort, then two-pointer for each fixed element
    return []

print(three_sum([-1, 0, 1, 2, -1, -4]))  # [[-1,-1,2],[-1,0,1]]
print(three_sum([0, 0, 0]))               # [[0,0,0]]