CAB203 Distrete Structures assignment problem that uses breadth first search to calculate minimum distance from one person to every other person in a family tree.
Bob lives in an isolated community on board a generation ship — a spaceship travelling to a distant starover several lifetimes. Naturally over the generations the community has come a point where everybody is related to everybody. Bob has recently become interested in genealogy and has constructed a complete family tree for the community going back to the first generation, using the ship’s meticulous records. Histree records the parents and children of every person, from which it is possible to work out how any two people on the ship are related.
Since then Bob has become obsessed with understanding how he is related to the other people on the ship,and these relationships are quite complicated! For example, Alice is not only his second cousin (his mother’s father’s mother’s son’s daughter’s daughter) but also his first cousin once removed (his father’s mother’s mother’s son’s daughter), in additional to numerous other relationships.
Bob has decided to simplify his understanding of these relationships by adding annotations to his family tree by marking the parent-child relationships that link people most directly to him. Here he considers a parent-child relationship (which we’ll call astep) to be direct, and other relationships are measured by howmany parent-child relations it takes to get from a person back to Bob. For example, Alice’s relationship toBob takes 5 steps via Alice’s father, and 6 steps via her mother, so — assuming there are no more direct relationships — Bob’s annotated tree will mark the relationship between Alice and her father, and there willbe no mark on the relationship between Alice and her mother. This way Bob can quickly see the most direct relationship that he has with any person.
Bob realises that there may be more than one relationship between himself and another person that are equally direct, in which case he is happy with any one of them. Further, Bob has realised that his definition of relationship includes some cases that others might not consider as being a family relationship, particularly through half-siblings. However, Bob has decided to stick with his definition. Basically, just don’t worry about these cases.
Help Bob to create his simplified family tree: given the complete family tree, find a simplified tree where there is a unique way of relating Bob to each other person, and that relationship is most direct among all possible relationships in the complete family tree.
Bob’s family tree is in the form of cards. Each card lists a person’s name, father, mother, and children (plusother information such as date of birth that we can ignore here.) Bob would like to have new cards that show the same information, but have a * in front of the names of people where the relationship needs to bemarked. For example, on Alice’s card, Alice’s father’s name will have a * in front, and on Alice’s Father’scard there will be a * in front of Alice’s name.
