Changelog

Graph Theory: practise each lecture the way the midterm asks it

• The Lecture 5 to 9 drills now have an Exam-style mode beside the drill: questions from the Midterm mock for that lecture only, one at a time, marked as you go.
• Each question says which midterm question it trains, how many marks it is worth and which textbook exercise it follows.
• Get one wrong and you can try again or see the worked answer; part marks show which parts were wrong.
• Each lecture page lists the midterm questions it covers, with a link to sit the full mock when you're ready.
• In the Exam Simulator, check any question on its own as you go: it locks and shows the worked answer, and New version gives you the same question with new numbers and graphs.
• The Midterm mock is now one fixed paper: every sitting asks the same questions in the same order, and only the numbers and graphs change, so a second sitting shows whether you've really got it.

Try Bridges & Trees, exam-styleOpen the Exam Simulator

Graph Theory: a cram sheet for every lecture

• New cram sheet for Lectures 1–3 and 5–9: each lecture split into a few sections, each idea explained in one plain line first.
• Under each section, the exact definitions and theorems from the lecture decks, in the same wording as the flashcards.
• The trap that loses marks is flagged under the definitions that have one.
• Every lecture links to the drills that practise it, and a bar at the top jumps between lectures.

Open the cram sheet

Programming 2 is open: eight units of C drills

• CIS 1201 now has its own drills, built from the Canvas review decks and a classmate's worked Prog 2 code.
• Eight units in course order: arrays and pointers, arrays in functions, characters and strings, searching, elementary sorting, structs and unions, file handling, and linked lists.
• Sorting asks what the deck asks: the array after the 1st pass of bubble sort, the 2nd of selection sort, the 3rd of insertion sort.
• Every program question is a real C program, marked by what it actually prints. Step through it in the tracer once you have answered.
• Progress saves like the other subjects and syncs to your account if you are signed in.

Open Programming 2

New subject: Discrete Structures III (CS 3101N), linear algebra with notes and drills

• Five units in the order the Canvas modules teach them: systems of linear equations, operations with matrices, the inverse, determinants, and vector spaces.
• Notes for every unit, written from the lecture slides: definitions, the row-operation notation the course uses, worked examples, and the traps that cost marks.
• A drill for every unit. Every question draws new matrices and vectors, and the answer is worked out in exact fractions, so ½ stays ½ instead of 0.4999.
• A hands-on bench: row-reduce an augmented matrix or [A | I] yourself. Click an entry to make it a 1 or clear it with another row, drag rows onto each other to swap, and watch each step written like R1 ↔ R2 or −2R1 + R3 → R3. Undo, or ask for the next step when you're stuck.
• Progress counts on the home page like every other subject, and syncs if you're signed in.

Open Discrete Structures IIIRow-reduce a matrix

New subject: Discrete Structures I (CIS 1103), with notes and drills

• Five units in the order the Canvas modules teach them: sets, relations, functions, formal logic, and Boolean algebra with logic gates.
• Notes for every unit, written from the lecture decks: definitions, tables of laws and properties, worked examples, and the traps that cost marks.
• A drill for every unit. The questions draw new sets, relations, functions, truth tables and circuits each time, and the right answer is worked out, not looked up.
• Drawn diagrams: Venn diagrams with their regions shaded, and every logic gate and circuit drawn the way the slides draw them, in the notes and in the questions.
• Two hands-on drills: shade a Venn diagram for a set expression, and build a gate circuit for a Boolean expression on a breadboard, where you drag gates, wire them pin to pin and flip switches to see the signals live.
• Progress counts on the home page like every other subject, and syncs if you're signed in.

Open Discrete StructuresBuild a circuit

Cisco IOS lab: ping with a click, Packet Tracer's Simple PDU

• A Simple PDU button above the bench: press it, click the source device, then the destination, and it pings without typing a command.
• Each one lands in a PDU list under the bench marked Successful or Failed, with Fire again to re-send it once you have fixed something.
• It aims at whichever of the destination's addresses answers, so clicking a router just works.
• In the sandbox's Simulation mode, the packet steps across the bench as it does for a typed ping.
• It works on every lab task too, not only in the sandbox.

Open the sandbox

Cisco IOS sandbox: problems to build from scratch

• Five problems in the sandbox, each starting from an empty bench: two PCs on one cable, a small office, one router with two LANs, two sites over serial, and two VLANs with router-on-a-stick.
• You choose the devices, the cables and the ports. Goals are checked against whatever you build, so any layout that works passes.
• Packet Tracer style scoring: a point per configuration item, two per connectivity test, and a completion percentage.
• Each problem keeps its own bench, and the free build stays as you left it.
• Stuck? Show a way to build it. Like the lab tasks, it then counts as practice, not a pass.

Open the sandbox

Cisco IOS lab: build your own topology, Packet Tracer style

• A sandbox: an empty bench where you drag routers (1941), switches (2960), layer 3 switches (3560) and PCs on, move them about and delete them. It is kept in your browser.
• Cables run port to port from a menu of each device's ports. Pick them as Packet Tracer wants: straight-through between unlike devices, crossover between like ones, serial between routers. The wrong one leaves the link down.
• Link lights at both ends of every cable, green when it is up and red when it is down.
• A console cable from a PC's RS 232 to a router's or switch's Console adds a Terminal to the PC, and you configure the device from there.
• Simulation mode: ping, and the packet steps hop by hop across the bench, out and back, with an Event List that shows where it was dropped.
• Three new tasks open the lab: cable a LAN, join two switches with crossover, and run a serial WAN with its clock rate and a console cable.

Open the sandboxTry the cabling tasks

A new tool, the Cisco IOS lab: configure routers and switches from the command line

• Twenty-two tasks on a command line that answers like Packet Tracer: from enable and configure terminal up to a full basic router setup.
• Each task sits on a topology you can click: routers and switches open their command line, PCs open IP Configuration and a Command Prompt, and ping really crosses the network.
• The basic config from the class notes (hostname, banner, enable secret, console and VTY 0 15 with Telnet, password encryption), then interfaces, loopbacks, a serial link, and static and default routes.
• VLANs and inter-VLAN routing: create and name VLANs, assign ports with interface range, trunk between switches, router-on-a-stick subinterfaces and a layer 3 switch with ip routing.
• Scored like a Packet Tracer activity: points and a completion percentage that climb as each item is configured, plus connectivity tests such as PC-A pinging PC-B. Marked on the configuration you end with, so g0/0 and GigabitEthernet0/0 both count.
• ? lists what can come next, Tab finishes a word, and mistakes get IOS's own errors, caret and all.

Open the Cisco IOS lab

Graph Theory: a midterm mock set like the pre-midterm

• The Exam Simulator opens on a new Midterm mock. Questions 1 to 9 and the bonus copy the pre-midterm's layout and its 76 marks, filled with Lectures 5 to 9.
• The pre-midterm came from the textbook, Chartrand & Zhang's A First Course in Graph Theory, so the mock does too: Lecture 5 to 9 exercises from its Chapters 3, 4 and 5, with the numbers changed.
• Question 1 is one graph with 21 parts, a to u. Question 2 has you draw on it, Question 4 rebuilds a graph from its deck of vertex-deleted subgraphs, and Question 7 runs both Kruskal's and Prim's Algorithms.
• Questions 10 to 19 are extra drill: prove-or-disprove statements, short answers, example-or-none drawings and the street-repairs problem. One sitting is 124 marks over two hours.
• Every question names the exercise it follows, and the answers were checked against the book's solutions.

Open the Exam Simulator

Graph Theory: Lecture 5 and a Lectures 5–9 paper set like the real exam

• A new Isomorphism drill for Lecture 5: decide whether two graphs are isomorphic, and if they are, build the vertex-bijection that proves it.
• Lecture 5 is in Definition Traps, Flashcards and the formula sheet too: equal vs isomorphic, structure-preserving bijections, and why the same degree sequence is never proof.
• The Exam Simulator's second paper now covers Lectures 5 to 9 and is laid out like the departmental exam: numbered questions, lettered parts, marks on each.
• Question 1 is one graph and twelve short answers, written as sets like uv, wx or as yes and no; Question 2 has you draw on that same graph.
• Question 4 is six cases where you either draw a graph or say none exists, and Question 8 is isomorphism. A bonus question counts on top of the total.

Open the Isomorphism drillOpen the Exam Simulator

A new look, faster ways in, and drills that run in rounds

• Every page has a new look: deep navy with lavender buttons and rounded corners. There's one look for everyone now, so the accent colour picker in Settings is gone.
• Every subject now shows on the first screen of the home page as its own card, under the area tabs. Each card links straight to its first few drills.
• Pick up where you left off: the home page remembers the last drill or tool you opened on this device and puts a Resume button at the top.
• Drills now run in rounds of 10: your streak shows on the progress bar, questions you miss come back, and each round ends with a summary and a button to relearn just the ones you got wrong.
• The IAS deck has a focus mode: one big card, Space to flip, then Still learning or Know it. Your known, learning and not-seen counts sit beside it.
• Each subject's page shows its modules as cards, with your progress, weakest topic and reset button in one panel at the top. The tracer and visualizer now sit under Tools on the home page.

Open the home page

Graph Theory: Lectures 6 to 9

• Four new drills, one per deck: Bridges & Trees, Minimum Spanning Trees, Cut-Vertices & Blocks, and Connectivity κ and λ.
• Minimum Spanning Trees has you run Kruskal or Prim by hand, clicking edges in the order the algorithm picks them, then giving w(T).
• Cut-Vertices & Blocks is Exercise 3 from Lecture 8: mark the cut-vertices and bridges on the figure and count the blocks.
• Definition Traps and Flashcards have new questions and cards for Lectures 6 to 9, and the formula sheet has four new sections.
• The Exam Simulator can now set a Lectures 6–9 paper, a Lectures 1–3 paper, or one covering everything.

Open Graph Theory

A door to bored, for the break between sessions

• The home page now links to bored, our sister site of small games: word search, colour and timing memory, chess puzzles and sliding tiles.
• Pass a Programming 1 stop quiz or module checkpoint and a quiet link offers a short game before the next one.
• bored opens in a new tab, so your place in study hub stays where you left it.
• The subject list is split into Programming, Theory and Networking tabs. Pick one and only its subjects show; the page remembers your pick.

IAS: a second cram set, and a clearer cram sheet

• The cram sheet is now split into each module's course sections, each with one line on what it is about, so facts have context.
• Facts read as term and meaning, and each section's quiz questions sit right after its facts, so you can read and check in one go.
• Cram set 2 picks up where set 1 stops: 240 more facts across modules 8 to 14 and 18, none repeated from set 1.
• Each module ends with practice answers, about 15 bank questions that test the new facts, with the same hide and reveal as set 1.
• Switch between Set 1 and Set 2 at the top; module links and Hide answers stay pinned as you scroll.

Open cram set 2

IAS: cram mode, the NetAcad quiz questions, and every topic covered

• New cram sheet for modules 8 to 14 and 18: the must-know facts, the traps, and every NetAcad quiz question with its answer, nothing else.
• Hide the answers on the cram sheet to test yourself, and open any one with a tap.
• Multiple choice for modules 8 to 14 and 18 now covers every topic in the NetAcad module text, so the bank grows from 463 to 1,009 questions.
• New Course quiz type: the questions from each module's Check Your Understanding and Module Quiz, cut to four options with the official explanation.
• Choose-two and choose-three questions are kept as combined answers, so you still have to know every part.
• Filter to Course quiz to drill exactly what NetAcad asks, or leave All on to mix it with descriptions, acronyms and scenarios.

Start crammingDrill the course quiz

IAS: a real multiple-choice quiz

• Multiple choice in the IAS deck now has its own bank of 463 questions across all 14 modules, written for the quiz instead of borrowed from the flashcards.
• Description questions turn it around: you read what something does and pick the term it describes.
• New acronym questions — what AAA, HIPS, NTP or IOC stands for, with near-miss expansions to trip you up.
• New scenario questions put you in a situation and ask which attack is happening or which control fits.
• Filter by type, and after each answer a short line explains why it is right. Wrong answers collect under Missed only.

Try the quiz

IAS: notes for every module

• A new Notes section for Information Assurance & Security: all 14 modules written out to read before the deck asks about them.
• Each module goes topic by topic, with the tables worth memorising, the formulas, and a Trap line for the mistakes that cost marks.
• Diagrams where a picture helps — the TCP handshake, the cybersecurity cube, onion vs artichoke, the DMZ, RAID levels, AAA, ACL placement and digital signatures.
• Models you can try: flip rwx bits into chmod numbers, turn a prefix into a wildcard mask, send a packet down an ACL, and work RSA and Diffie-Hellman with your own numbers.
• Every module ends with questions to answer from memory and a link straight to that module's cards.

Read the notes

Automata: the 6-tuple for Moore and Mealy machines

• A new 6-tuple exercise on the Moore & Mealy page: read a machine off its diagram and write out Q, Σ, Δ and q₀.
• Then fill in δ and λ as a table — one λ column for a Moore machine, one per input for a Mealy machine, so you see where the output lives.
• Each field and cell is marked on its own, with the right answer under anything wrong and the whole machine shown as a table after.
• Mix up Σ and Δ and the marking says so.

Try the 6-tuple

Automata: minimising a DFA, and Moore and Mealy machines

• Two new Automata Theory modules for the lessons after ε-NFA → DFA, which makes seven.
• Minimise a DFA: write out 0-equivalence, 1-equivalence and so on until a round repeats, then fill in the merged table and draw the minimal DFA. Each step is marked before the next opens.
• Moore & Mealy machines: run inputs through a machine and write what it prints. After marking, each walk is written out with the output under the state or arrow that printed it.
• Convert between the two: Moore → Mealy cell by cell, and Mealy → Moore in two steps, first which states have to split and then the new table.
• The method sheet has both lessons, with the usual column of traps.

Minimise a DFAMoore & Mealy

The tracer handles big CisCode programs

• A program with a table of records no longer freezes the tracer. Variables are summarised: a char array reads as its string, a struct sits on one line, and an array of structs or a heap full of nodes becomes a table. Click a name or a row to see every cell, '\0' included.
• A long linked list is drawn to fit: both ends, the nodes around each pointer, and the rest folded into a stub you can open. The list hangs from its header struct, trav is named under the node it is on, and that node's whole record is written out below.
• Skip the part you were told not to touch. The tracer opens after functions the code marks as predefined (and says so), and a Jump to menu lists every call in the run.
• Step over a call with Shift →, step out of one with Shift ↑, and click a line's number to run to it.
• A drawing too wide for its column moves across the top of the page; "Beside the code" puts it back. Printed tables keep their columns and the output follows the newest line.
• More of the C that CisCode's problems use now runs: function pointers, compound literals, qsort, strcspn and strtok, size_t and INT_MAX, rand with the numbers Linux gives for a seed, and recursion about a thousand calls deep. A missing #include is a warning above the trace, not a refusal to run.

Open the tracer

Your own C, drawn and coloured

• The C tracer now draws the data structures in your own code the way the visualizer draws the course's: array and linked lists, cursor-based lists, stacks, queues, sets, hash tables, trees, heaps and graphs. It goes by what your code does, not what you call things, so plates[] and height are a stack; nodes that are records show every field; and where it can't tell, "Draw this as…" lets you say. Buggy code is drawn too, with cycles, freed nodes and lost nodes labelled.
• C code is coloured like an editor colours it. A new settings page lets you pick a colour scheme (including VS Code's), change any single colour, and choose the code font and its size.
• The C visualizer picks a structure from four menus instead of a wall of buttons, keeps its step keys in view as you scroll, and on lists it now plays what each step changed: a node sliding in, a pointer swinging to its new target.
• CisCode problems can open here: your code and a failing test case land in the tracer, which finds the step where your output stops matching.
• Programming 1: topic and module filters are one menu each, a drill you are stuck on can be skipped, and pressing Run in the tracer brings the trace into view.
• This list. A dialog tells you what changed since your last visit.

Open the tracerSettings

The C visualizer

• Every structure in Data Structures and Algorithms, step by step beside its C: lists, stacks, queues, sets, dictionaries, trees, BSTs, priority queues, heapsort and graphs.
• Pick how the structure is built (array, linked, cursor-based) and the operation, then change the starting items and arguments to see another case.
• Linked from the home page, from DSA and from the Go to… palette.

Open the visualizer

IAS: modules 8–14 and 18, and cryptography drills

• Cards for modules 8 to 14 and 18 join the deck.
• Six cryptography drills for Module 18.
• An index page in front of the deck, so you can start from a module.

Open IAS

Data Structures and Algorithms

• DSA goes live with twelve units of drills.
• In drills, labels come filled in, the run is shown on demand, and options take letter keys.
• An anonymous suggestion box, with its own band on the home page.

Open DSA

Programming 1, and a tracer that draws

• Programming 1 follows the course's own modules, with a study mode of stops, quizzes and checkpoints.
• The C tracer draws pointers as arrows and data structures the way they are drawn on the board, beside the code.
• The tracer has its own place on the home page, and shortcut hints name the key on your keyboard: ⌘ on a Mac, Ctrl elsewhere.

Open Programming 1

A year of days, and a better phone

• The home page draws a year of days, one square each, for the days you got something right.
• On a phone the subject bar opens a navigation sidebar.
• One switch puts every drill under exam conditions, and a wrong answer in a graph drill can be retried.

Battle

• Race classmates through the same drill, live. Every drill is a stage.
• Sprint: a solo race against the clock.
• High scores, sound, and a cabinet that works on a phone.

Open Battle

study hub opens

• IAS, Graph Theory and Automata Theory in one place, under one design.
• An accent colour you choose per device.
• Automata: run a string through the machine, and write the ε-NFA table out one box at a time.