Linked Lists Interview Questions & Solutions

Linked list problems are a test of careful pointer manipulation more than clever algorithms. There's no random access, so everything is about walking nodes and rewiring `next` pointers without losing track of the rest of the list. The number-one cause of bugs here is dropping a reference before you're done with it — which is exactly what interviewers are checking you can avoid.

The solutions below drill the handful of techniques that cover most interview questions: reversing a list (iteratively and recursively), the fast-and-slow two-pointer trick for finding the middle and detecting cycles, merging sorted lists, and removing the n-th node from the end in a single pass. A recurring tip you'll see throughout is the dummy head node — a small trick that eliminates a whole class of edge-case bugs when the head itself might change. Draw the pointers on paper as you read, and the "gymnastics" become routine.