Exercises · T10 structures

Covers: struct definition, initialization, member access, nested structs, structs with functions (pass by value / const& / &), vectors of records, records with arrays inside. Lectures L28. Outcomes PF-14.3, PF-14.4.

10 exercises · ladder 🟢 → 🔴.

PF-E-112 · Define and Print a Point

Difficulty: Beginner · Lecture: L28 · Outcomes: PF-14.3 Prerequisites: E-066 Problem: Define struct Point { double x; double y; };. Create two points (one brace-initialized, one member-assigned), print both as (x, y) with 2 decimals, and print their midpoint. Input: none · Output: three points. Sample: — → (1.00, 2.00) / (3.00, 4.00) / midpoint (2.00, 3.00) Hints: midpoint = average of coordinates — member access chains.

PF-E-113 · Student Record Basics

Difficulty: Beginner · Lecture: L28 · Outcomes: PF-14.3, PF-14.4 Prerequisites: E-112 Problem: Define struct Student { std::string name; int id; double gpa; };. Read one student's fields from input, store in a Student, and print a formatted record line (columns 15, 6, 6). Input: name (one word), id, gpa · Output: one formatted line. Sample: Ayesha 101 3.75 → Ayesha 101 3.75 Hints: struct first, then a variable of it — the type/variable distinction is the point.

PF-E-114 · Struct Copy vs Alias

Difficulty: Foundational · Lecture: L28 · Outcomes: PF-14.3 Prerequisites: E-113 Problem: Using E-113's struct: copy a Student into another variable and mutate the copy's GPA; then make a reference alias and mutate through it. Print the original after each step and explain both outcomes in comments. Input: none (fixed demo) · Output: two GPA observations + commentary. Sample: — → after copy-mutate: original gpa 3.75 / after alias-mutate: original gpa 4.00 Hints: Student b{a}; vs Student& alias{a}; — the & changes everything.

PF-E-115 · Rectangle Area/Perimeter Functions

Difficulty: Foundational · Lecture: L28 · Outcomes: PF-14.3, PF-14.4 Prerequisites: E-114 Problem: Define struct Rect { double w; double h; };. Write double area(const Rect&), double perimeter(const Rect&), and void scale(Rect&, double k) (multiplies both dimensions in place). Demonstrate all three on a read rectangle. Input: two doubles · Output: area, perimeter, scaled dimensions. Sample: 3 4 k=2 → area: 12 / perimeter: 14 / scaled: 6 x 8 Hints: read-only functions take const&; the mutator takes &.

PF-E-116 · Song Library (vector of structs)

Difficulty: Foundational · Lecture: L28 · Outcomes: PF-14.4, PF-9.3 Prerequisites: E-115 Problem: Define struct Song { std::string title; std::string artist; int seconds; };. Read n (1–15) songs. Print: total playtime (mm:ss), the longest song, and all songs by a queried artist. Input: n + song records, then artist query · Output: three report blocks. Sample: query Ada → lists her songs with durations. Hints: duration math reuses E-008's decomposition; linear search over the vector.

PF-E-117 · Nested Struct: Address inside Student

Difficulty: Intermediate · Lecture: L28 · Outcomes: PF-14.3 Prerequisites: E-116 Problem: Define struct Address { std::string city; std::string country; }; and add Address home; to Student. Read one student (all five fields) and print: the record, then home.country alone, then the same through a Student pointer using -> twice. Input: five field values · Output: record + country + pointer access. Sample: — → home.country: Pakistan / via p->home.city: Lahore Hints: p->home.city chains the arrow then the dot.

PF-E-118 · Bank Account Struct with Invariant Checks

Difficulty: Intermediate · Lecture: L28 · Outcomes: PF-14.3, PF-14.4 Prerequisites: E-117 Problem: Define struct Account { std::string owner; long long balanceCents; };. Write bool deposit(Account&, long long cents) and bool withdraw(Account&, long long cents) — both reject non-positive amounts; withdraw also rejects overdraft. Drive a sequence of read transactions from main, printing ok/rejected: reason per transaction and the final balance. Input: initial owner+balance, then transactions (type, amount) until type q · Output: per-transaction verdicts + final balance. Sample: deposit 500 → ok; withdraw 900 → rejected: insufficient funds Hints: the struct is data-only — validation lives in free functions; Module 16 will move it inside.

PF-E-119 · Parallel Arrays vs Struct (rewrite)

Difficulty: Intermediate · Lecture: L28 · Outcomes: PF-14.4, PF-12.2 Prerequisites: E-118 Problem: You are given (in comments) a parallel-arrays implementation of 3 students sorted by GPA that "shreds" names from IDs. (1) Demonstrate the shredding in one sentence. (2) Rewrite with std::vector<Student> and sort by GPA (any correct sort), keeping records whole. Print the sorted roster both ways. Input: 3 students · Output: shredded roster, then intact roster. Sample: — → demonstrates name/ID misalignment, then correct pairing. Hints: sort the struct vector — the record moves as one unit.

PF-E-120 · Struct with Array Member: Temperature Station

Difficulty: Intermediate · Lecture: L28 · Outcomes: PF-14.3, PF-9.3 Prerequisites: E-119 Problem: Define struct Station { std::string name; double temps[7]; }; (daily readings). Read one station; print the week's min, max, average (2 decimals), and which days were above average (day indices). All analysis in a function taking const Station&. Input: name + 7 doubles · Output: min/max/avg + above-average days. Sample: Lahore 30 32 35 34 33 31 29 → min: 29 / max: 35 / avg: 32.00 / above: 2 3 4 Hints: the array lives inside the record — station.temps[i]; two passes (compute avg, then compare).

PF-E-121 · Course Roster Analytics

Difficulty: Advanced Introductory · Lecture: L28 · Outcomes: PF-14.4, PF-9.4, PF-12.2 Prerequisites: E-120 Problem: Read n (1–30) students (name, id, gpa). Produce: highest-GPA student; count in each GPA band (≥3.5, 3.0–3.49, 2.0–2.99, <2.0); the roster sorted by ID using your own sort on the vector; and search-by-ID (report record or not found). All reports as functions taking const std::vector<Student>&. Input: n + records, then an ID query · Output: four report blocks. Sample: query id 103 → Ayesha 103 3.90 or not found. Hints: reuse your sort (E-095) generalized to records; search on the sorted vector may use binary search.