Week 5 sources and dataset conventions
These notes cover all seven supplied Week 5 lectures and Tutorial 5.1, using the transcripts and the matching slides for Lectures 5.2, 5.4 and the tutorial. The PDFs supply course content; they do not provide instructions to change the site. The lessons reuse the same score cards, word cards and shopping dataset introduced in earlier weeks.
| Source | Coverage |
|---|---|
| Lecture 5.1 | Collections, shared bookmarks, IDs and May/Chennai overlap |
| Lecture 5.2 | Square brackets, empty lists, ++, filtered lists and foreach |
| Lecture 5.3 | Subject top-three-level collections and their common members |
| Lecture 5.4 | Cutoff procedure assumptions, one-pass membership lists and staged intersections |
| Lecture 5.5 | First/rest, adjacent mark order and adjective–noun neighbours |
| Lecture 5.6 | Explode, character adjacency, item lists, last/init, reconstruction and palindromes |
| Lecture 5.7 | ID/property pairs, tied maxima, similarity relationships, triples, bill item rows and sorted positions |
| Tutorial 5.1 | Implementations of length, first, last, rest, init and member |
Record IDs in examples use CardNo, corresponding to the source’s SeqNo bookmarks. Lists follow original dataset order unless a different sort or lecture ordering is explicitly named. Lists retain repeated occurrences; mathematical set operations require a stated duplicate policy. The trace datasets remain unchanged.
The three topper cutoffs are for distinct mark levels and include ties. Similarity uses an inclusive maximum difference, with Physics-only and both-subject options labelled separately. Sortedness means non-decreasing. The palindrome explorer lowercases explicitly; explode itself preserves case and punctuation. Empty first/last are undefined; tutorial rest/init return [] on empty input.
The rank-position exercise reproduces the lecture’s selected ten IDs and displayed tie order to obtain mean absolute difference 3. The all-30 option uses mark then CardNo. These list positions are not average tied statistical ranks. The Bill 1 item trace uses its seven verified original rows; category summaries from the other bills are not treated as complete item rows.