Midterm review guide

Exam format: 100 minutes · 50 marks. Conceptual ≈ 40 %, applied ≈ 60 %. Question shapes: MCQ, output tracing, debugging, short conceptual, algorithm design (IPO/decision tables), coding, code completion. A closed-book paper — no compiler, so practice writing code by hand.

What to be fluent in

Module	Must-have skills	Practice from
M1 · Intro & toolchain	4 translation stages; error classes (syntax/runtime/logic)	Quiz 01, L01–L02 notes
M2 · Variables & I/O	brace init vs narrowing; `cin >>` whitespace rules; `fixed`/`setprecision`	Quiz 02, exercises T01
M3 · Operators	precedence, integer division vs `%`, cast for averages	Quiz 03, `examples/precedence_demo.cpp`
M4 · Decisions	ladder ordering, switch fall-through, short-circuit guards	Quiz 04, exercises T02
M5 · Loops	for/while/do-while boundaries; priming read; missing-update class	Quiz 05, exercises T03
M6 · Problem solving	IPO charts, trace tables, boundary test sets, decomposition	Quiz 06, case studies Tier 1–2
M7 · Functions	prototypes, pass-by-value vs reference, contracts, overloading	Quiz 07, exercises T05
M8 · Advanced functions	recursion base cases, scope/shadowing, default arguments	Quiz 08, `examples/recursion_towers.cpp`

Hand-trace drills (answers at the week's lecture notes)

int s{0}; for (int i{1}; i <= 3; ++i) s += i * i; → ?
int n{25}, c{0}; while (n > 0) { n /= 2; ++c; } → c?
int g(int n){ return n <= 0 ? 0 : n + g(n - 2); } — g(7)?
void tweak(int a, int& b){ ++a; ++b; } with p = q = 4 → p, q?

Debugging patterns to recognize

Shadowed accumulator (redeclared inside the loop).
Missing loop update (sentinel never re-read).
Integer division where a mean was intended.
Missing recursion base case.
>= vs > boundary off-by-one.
Fall-through switch without break.

Coding practice set (closed-book)

Temperature C→F with input validation, 1 decimal.
Median of three integers.
Sentinel-0 stats: count, sum, mean (2 dp) or no data.
bool isPerfect(int n) + all perfect numbers ≤ 10000.

Exam technique

Trace questions: write the variable table, not just the answer.
Coding questions: a correct skeleton with one small defect earns most marks — always declare, read, compute, print in that order and validate the read.
Budget: ≈ 2 minutes per MCQ-block item, 15 minutes per coding item.

See also ../final/review_guide.md after Week 8.