Welcome to your interview.
The question is on your right: Embedded Path Existence. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Given a list of connected coordinate pairs representing edges in a graph, such as (x1, x2), (x3, x8), and (xa, xn), write a program to determine if a valid path exists between two specific points, such as x2 and x15.