def threeSum(nums):
    """
    :type nums: List[int]
    :rtype: List[List[int]]
    """
    # Always end at net zero from the sum
    # first = 0
    # endpoint = len(nums)-1
    # solutionSets = []

    # # Handle edge-case of small list with only 3 variables
    # if len(nums) == 3 and sum(nums) == 0:
    #     solutionSets.append(nums)
    #     return solutionSets

    # while first != len(nums)-2:
    #     for i in range(first+1, len(nums)):
    #         if nums[first] + nums[i] + nums[endpoint] == 0 and [nums[first], nums[i], nums[endpoint]] not in solutionSets:
    #             solutionSets.append([nums[first], nums[i], nums[endpoint]])
    #         else:
    #             endpoint -= 1
    #     first += 1
    # return solutionSets

    # Solution
    nums.sort()
    answer = [] 

    # Loop through until the last triplet, solution relies on negative indexes
    for i in range(len(nums) - 2): 
        if nums[i] > 0: # end the loop if the values are positive
            break
        if i > 0 and nums[i] == nums[i-1]: # skip the current i index if it's the same as the last one
            continue
        l = i + 1 # Begin the left index at i + 1
        r = len(nums) - 1 # Begin the right index at the end
        while l < r:
            total = nums[i] + nums[l] + nums[r]
            if total < 0: # If the total is negative, we increase the negative side to get closer to 0
                l += 1
            elif total > 0: # If the total is positive, we decrease the positive side to get closer to 0
                r -= 1
            else:
                triplet = [nums[i], nums[l], nums[r]]
                answer.append(triplet)
                while l < r and nums[l] == triplet[1]: # Continue increasing the left index until a different 
                    l += 1 # number is found to avoid duplicates
                while l < r and nums[r] == triplet[2]: # Same with decreasing the right index
                    r -= 1
    return answer
    
print(threeSum([-1,0,1,2,-1,-4]))
print(threeSum([0,0,0]))
print(threeSum([0,0,0,0]))
print(threeSum([1,2,-2,-1]))