Practice: Pairs and Structs

Fourteen problems about bundled values. Read each record into a pair or a struct and keep it whole; no problem here needs sorting yet.

• Even Pairs, Top Students, Reflected Points, Swap Coordinates: read pairs, test or transform each one, print it. Coordinates go up to 10⁹ in size, and Swap Coordinates reaches ±2³¹, so read them as long long.
• Highest and Lowest Score: the Week 4 maximum and minimum loops, each keeping an index; the strict > and < keep the first of equal scores.
• Best Student: ties on the score go to the lexicographically smaller name. Compare {score, name} pairs — or, since a larger score must win, {-score, name} pairs with <.
• Student Cards, Athlete Summaries, Contest Totals: a struct per record, read and printed back with something computed. Up to 3·10⁵ lines: keep the fast-IO lines.
• Most Valuable Product and Largest Rectangle: price * quantity and w * h reach 10¹⁸, so the fields are long long before multiplying.
• Point Distance: a struct Point and q queries; the squared distance also needs long long.
• Intervals Length and Coverage: one struct, two answers (a total and a count) from a single loop.
• Library Borrow Records: a Member struct with a vector<int> of borrowed book indices inside it — a field can be a vector.