1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution I don't understand how when p1 hits the end of the linked list, p2 will be at the midpoint. This is how I am imagining it if n=3. Each step below represents an iteration. 1. a1 (p1, p2)->a2->a3->b1->b2->b3 2. a1->a2 (p2)->a3 (p1)->b1->b2->b3 3. a1->a2->a3 (p2)->b1->b2 (p1)->b3 4. Index out of bounds error because p2 now points to a node after b3.