Java Data Structures: The Very Simple Book
A from-scratch Java and data structures book built around dry-running code by hand rather than memorising it. Starts at the ground floor — every keyword, every operator, decisions and loops, methods and the call stack, recursion, arrays and strings — before building objects and reasoning about cost (Big-O, brute force vs. optimised). The core of the book hand-builds every major structure from nothing (linked list, stack, queue, hash table, trees, heap/priority queue, graphs, trie), then covers the Java Collections Framework you'd actually use day to day. Closes with 100 worked programs across numbers, arrays, strings, and structures, plus a chapter on the mistakes that cost the most hours and how to dry-run properly.
My wife wrote this one, and I added it because it solves a real problem the other DSA resources on this site don't: it starts from zero, not from "assumes you already code comfortably." The dry-run-by-hand approach — tracing code manually instead of memorising patterns — is the part that actually builds intuition, and it's rare to see a book commit to that as fully as this one does. If the other Java DS courses here felt like they skipped a step, this is the step they skipped.