7 days with Linked List (Kiao, Ue Chatterjee, Aditya) (z-library.sk, 1lib.sk, z-lib.sk)

【One-Line Pitch】 A compact, day-by-day workout that turns linked-list basics into interview-ready pattern recognition, best suited to students and early-career engineers who learn by solving one focused problem at a time. 【Book Arc】 - **Opening (~0%–10%)**: Sets the seven-day schedule and frames the linked list as an array alternative whose difficulty lies in pointer reasoning, then introduces node structures in C and object-oriented Java/C++. - **Early (~10%–30%)**: Builds the working vocabulary — search, insert, delete, singly vs. doubly linked lists, complexity tables, and the locality-of-reference argument for why arrays search faster — before the first real problem (inserting into a sorted list). - **Middle (~30%–55%)**: Shifts from mechanics to technique: a variant of the sorted-insert problem, then the two-pointer "tortoise and rabbit" method for finding the middle element in one pass instead of two. - **Late (~55%–85%)**: Moves into classic interview set pieces — detecting a loop by three different methods, moving the first element to the end, and reversing a doubly linked list. - **Ending (~85%–100%)**: Closes with reversing a singly linked list using the two-pointer technique and a short conclusion that ties the week's patterns together. 【Key Takeaways】 - **Pointer redirection is the whole game** (Early): Insert and delete both reduce to rewiring a predecessor's `next` (and `prev` in doubly linked lists); once that mental model is solid, most problems become bookkeeping. - **Know the complexity trade-off cold** (Early): Insertion and deletion are Θ(1) once you hold the node, but search is Θ(N) — and finding the node before a target is O(N) in a singly linked list, O(1) in a doubly linked list. - **Binary search is a trap on linked lists** (Early): It is technically possible on sorted data, but without random access each midpoint lookup costs linear time, so the total stays O(N) and plain linear search wins on simplicity. - **Locality of reference explains the array advantage** (Early): Arrays sit contiguously in memory and benefit from cache-friendly fetching; linked lists are scattered, so searching is inherently slower even at the same asymptotic cost. - **Two pointers replace random access** (Middle): The slow/fast pointer trick finds the middle in a single traversal and is presented as the key mitigation for the linked list's lack of indexing — a pattern worth memorizing. - **Loop detection has multiple routes** (Late): The book deliberately shows three methods for the same problem, signaling that interviewers care about comparing approaches, not just reaching an answer. - **Reversal is the canonical pointer exercise** (Late): Both the doubly linked list reversal and the two-pointer singly linked list reversal drill the same skill — holding three references steady while the list flips underneath you. - **Small problems carry transferable lessons** (Middle): The sorted-insert variant is used to show that an array-friendly idea may not port to linked lists, and that O(1) delete-and-append can restructure a list in place. 【Reading Tips】 - **Deep-read Day 1 and Day 3.** The node implementation, complexity table, and two-pointer technique are the load-bearing chapters; everything later reuses them. - **Skim the language boilerplate.** C struct and Java class listings repeat the same logic — pick your language and skip the other. - **Work the pseudocode before the Java.** The book gives pseudocode first; typing your own version before reading the provided implementation is where the learning happens. - **Treat Day 4's three methods as a comparison exercise.** Ask why each approach exists and what it costs, rather than memorizing one. - **Keep a pointer diagram beside you.** Every hard spot in this book is a reference-tracking problem; sketching boxes and arrows resolves most confusion faster than rereading. 【Coverage Limits】 This guide is based on stratified excerpts covering the schedule, fundamentals, and several mid-to-late problems; the full code listings and the concluding chapter are only partially represented, so specific implementation details beyond the sampled material are not summarized here.