Use a tree or a list or something else?

Question

Hello all...I need to create a sort of "family tree". I'm given a String[] where each entry will either be of the form "child parent" or "person gender". If its in the form "child parent" I know that the family tree has child as a child of parent. If its in the form "person gender", I know what that persons gender is. I need to go through this array of strings making sure that each child has at most two parents which must be of the opposite sex, and that no child is its own descendant (eg. If Bob is a child of Sue who is a child of Joe, Joe better not be a child of Bob). What I need to report is the index of the String[] where this fails.
Hopefully that's a clear explanation.
Here's an example:
{"BOB JOHN","BOB MARY","MARY JOHN","JOHN f","MARY f","AL f"}
Returns: 4
The first 4 elements are considered consistent. They describe that BOB's 2 parents are JOHN and MARY and that (unconventionally) MARY is JOHN's child. JOHN is female. But "MARY f" is inconsistent with this since that makes both of BOB's parents female.My first thought was to store this as a Tree but since a parent can have lots of children and a child can have two parents and I may be adding parents before I know their genders and then having to go through and modify things. It seems too complex. Then I thought to store it as an arraylist. But I still run into problems where if I modify things I have to search through many different places to make sure I reflect it everywhere and everything still holds true.
What do you guys think? I can post some other examples if its still unclear

Answer 1

You should probably approach this problem by breaking it down into some general processing steps. As an example, you probably can't check for required conditions - like gender, parentage, etc - until you have processed the whole set of input. That suggests you will have at least two stages:
Build up structures.
Do the condition checking.
What kinds of structures would you use to do the condition checking?
Hint: Just one structure probably isn't going to hack it.
Hint: For starters, yoou probably need a list of persons.
Hint: Each person should have a gender.
Hint: You need to be able to check for parents of each person.
Hint: You need to check for circles in the parenting.