Determine whether two nodes are related

Problem

You are given genealogy information for a set of chickens. The data consists of parent → child relationships (e.g., (parentId, childId) pairs). Not every chicken necessarily appears in every role, and the data may describe multiple independent family groups.

Write a function that, given two chicken IDs a and b, determines whether they have a blood relationship.

For this interview question, treat two chickens as “blood-related” if they belong to the same family lineage, meaning:

• one is an ancestor/descendant of the other, or
• they share at least one common ancestor (i.e., they are in the same connected family component).

Input / Output

• Input:
  • A list of parent-child pairs relations , where each pair (p, c) indicates p is a parent of c .
  • Two chicken IDs a and b .
• Output:
  • Return true if a and b are blood-related under the definition above, otherwise false .

Notes / Edge cases to consider

• Either a or b may not appear in relations .
• There may be multiple roots (a forest).
• A chicken may have 0, 1, or 2 parents depending on the dataset.
• Clarify/handle whether the input could contain cycles (invalid genealogy); your solution should not infinite-loop if it does.

Example

Given relations: (1,2), (1,3), (3,4), (10,11):

• Query (2,4) → true (share ancestor 1 )
• Query (2,11) → false (different family groups)
• Query (3,4) → true (ancestor/descendant)