Quiz — Lecture 09

Section A from memory, one line each. Section B shows your reasoning - marks are for method, not final answers. Answers are discussed in class; the exit ticket goes on a card.

Section A

A1. Name the four aggregation patterns.

A2. Why initialise best-so-far from the first element, not 0?

A3. Where is the average computed, and why there?

A4. What does one-pass mean, and what would two passes cost?

Section B

B1. Pages [12, 0, 25, 8, 30], target 10: give total, average, best day, days below target.

B2. Stock levels [4, 9, 9, 2]: report the argmax with a witness (its index), stating your tie rule.

Exit ticket

Answer one of these on your card in 60 seconds (choose any one):

1. Name the aggregation pattern for 'which day had the most sales'.

1. Why reset streak state?

1. What is two-pass thinking and when does it pay?

Homework

• Before: skim the four student pages; attempt case 1 on paper.
• After: write a five-line pseudocode solution for any case you did not
• Enrichment (optional): the stretch question on each case page.