Compare two linked lists of strings

First clarify the equality contract: normally two linked lists of strings are equal when they have the same number of nodes and corresponding strings are equal, not merely when their concatenated characters match. Traverse both lists together. At each step, reject if one pointer is null before the other or if the two string values differ; otherwise advance both. Return true only when both become null together. This avoids allocating joined strings and makes the node-boundary semantics explicit. If the interviewer instead means character-stream equality across different chunking, say that is a different problem and use per-node character offsets. Test empty lists, one empty list, empty-string nodes, and unequal tail lengths. The ordinary nodewise comparison is O(total characters compared plus node count) time and O(1) extra space.