Vietnamese chuyên Tin Topic Ordering vs Knowledge-Space-Theory Prerequisite Analysis: A Curriculum Audit

The Vietnamese specialised informatics (chuyên Tin) canonical topic order, abstracted across the Hô Sĩ đàm MOET textbook line (2010–2011), the Lê Minh Hoàng coursepacks (1999, 2002), and the VNOI wiki (2015 onward), follows a sequence — language and I/O, then arrays and elementary algorithms, recursion and backtracking, greedy and divide-andconquer, dynamic programming, graph algorithms, advanced data structures (Fenwick tree, segment tree, sparse table), strings, geometry, advanced topics — that places dynamic programming and graph algorithms structurally before the range-query data structures on which several of their advanced sub-topics depend. The C1.1 sibling crosswalk flagged this as a structural anomaly without proving it against a formal prerequisite graph. This paper supplies that proof. It constructs a Knowledge Space Theory (KST) prerequisite graph of 28 atomic topic nodes spanning seven strata (T0 language and I/O, T1 arrays and elementary algorithms, T2 elementary problem-solving paradigms, T3 elementary graph algorithms, T4 dynamic programming, T5 range-query data structures, T6 advanced graph and tree decompositions, T7 strings and geometry), derives the KSTinduced earliest admissible introduction position of each node, and compares it against the canonical Vietnamese introduction position. The audit identifies six ordering anomalies: A1 the range-query-data-structures inversion (DS taught after DP and graph despite tree DP and offline graph queries depending on them); A2 the backtracking-before-memoised-recursion-totabulated-DP framing (KST-compatible but pedagogically lossy on the recursion bridge); A3 the sparse-table absence from the textbook line despite its prerequisite status for LCA via Euler tour; A4 the strongly-connected-components positioning ahead of articulation/bridge despite SCC depending on DFStree machinery introduced through articulation/bridge; A5 the inline introduction of segment trees inside DP and graph chapters rather than as a standalone stratum; A6 the geometry-afterstrings ordering despite the two being independent. Each anomaly is classified as Keep, Reorder, or Re-scope on three evidence sources: the IOI Syllabus, the practitioner-pedagogy literature (Halim CP4, Laaksonen-CSES, USACO Guide, Skiena ADM, CLRS, Sedgewick), and the cognitive-load-theory anchor. The deliverable supplies the topic-ladder design for the Competitive Programming Pathway Vol 5+ chapter sequencing and a principled basis for any downstream chuyên Tin reform proposal. Scope is document analysis plus theoretical synthesis; no cohort work; the audit-loop substitutes for empirical validation per program scope.