Decision-tree leaf outcomes are now cached on the main thread keyed by
their full 12-course assignment. Pin operations filter the cache and
re-derive top-K + per-set ceilings instantly with no worker spawn. Unpin
operations show the cached subset immediately and stream improvements as
a background worker fills in the missing leaves. Cache survives pin,
unpin, and adopt-plan; only ranking or mode changes invalidate it.
Solver / worker:
- searchDecisionTree accepts skipKeys (Set<string>) and pinnedAssignments
(Record<setId,courseId>). Leaves are emitted with their full 12-set
assignment so cache keys are stable across pin/unpin operations.
- evaluateLeaf short-circuits when the leaf's assignmentKey is in
skipKeys: increments iterations + emits progress, but skips the
optimizer call and all callbacks. Keeps progress percentage honest
(counts whole tree, not just delta).
- New deriveFromLeaves pure helper produces {topK, setAnalyses} from a
leaf collection; used by the main-thread cache filter and gives a
reusable derivation primitive for tests.
- Worker request gains skipKeys and pinnedAssignments fields. Worker
response gains a leafEvaluated event so the main thread can populate
its cache as the search streams.
App state:
- leafCacheRef holds Map<assignmentKey, PlanOutcome> scoped to the
current (ranking, mode) pair. The search effect now: invalidates on
ranking/mode change; computes the orderedCourses + expectedTotal;
filters the cache against the current pinned/excluded state; calls
deriveFromLeaves to render immediately; spawns the worker only when
filtered.length < expectedTotal, passing skipKeys.
- Cache cap of 500,000 leaves with full clear on overflow. Bounds
worst-case memory at ~150 MB.
UI (TopPlans):
- Course blocks in the per-plan row are now interactive buttons. Click
pins (or unpins, if the course is currently pinned) the course in
that set. Pinned blocks render in a selected blue color.
- Each plan row now shows the FULL 12-set sequence including pinned
courses (interleaved with the search's recommended choices for the
remaining open sets) so the displayed plan is always complete.
- Spec qualification tags removed from per-block display (kept the
set-label + course-name treatment for clarity).
Tests:
- New app/src/solver/__tests__/leafCache.test.ts with 4 tests:
skipKeys parity (second-pass run with skipKeys evaluates zero
leaves), deriveFromLeaves parity (matches a fresh search), cache
filter on pinned assignments, cache filter on excluded courses.
- All 78 prior tests continue to pass; 82 total.
Browser-verified: pin click on a Top Plans block from the cached
8-open-set scenario completes instantly with no spinner; unpin restores
the original cached subset (also instant when the prior space was
already cached); mode toggle correctly invalidates and re-runs the
search.
The v1.3.0 saturation termination silently capped the search after only
the heuristic-favored part of the tree, leaving most per-set ceiling cells
stuck at "0 specs" and hiding genuinely-feasible 3-spec plans in
maximize-count mode. Replace with full exhaustive enumeration plus a
batch of UX refinements that emerged during testing.
Algorithm:
- Drop the saturation early-termination entirely. Search now runs the
full open-set cartesian product to completion; the iteration cap is
also removed so no scenario exits partial.
- Add mode-dependent DFS child ordering: priority-order keeps the
priority-target-first heuristic; maximize-count orders children by
descending count of qualifications for reachable specs (generalist
courses tried first).
- Make the (count, priorityScore) comparator mode-aware: priority-order
ranks by (priorityScore, count) so the user's top spec surfaces;
maximize-count ranks by (count, priorityScore) so the highest count
wins. The same rule drives both top-K position and per-cell ceiling
selection (and the Recommended badge).
- Add an evaluated boolean to each ChoiceOutcome and set it on first
leaf evaluation. Distinguishes "still searching" from "evaluated, no
specs achieved" so the UI never shows misleading 0 specs for a cell
the search hasn't reached yet.
- Throttled progress events (~100ms) carrying iterations / total leaf
count, drive both the per-set spinner and the global progress bar.
UI:
- Top Plans header shows a horizontal progress bar with
"iterations / total · NN%" while the search runs; collapses to
"Search complete · N explored" on completion.
- Per-set spinner next to each elective set heading while any choice
in that set is unevaluated.
- Per-cell pulsing dot + "searching" text for unevaluated cells.
- Replace the "(HCR, BNK, ...)" text labels on each course with
color-coded SpecTag pills using a new fixed per-spec palette
(app/src/data/specColors.ts). Same palette applied to the Top Plans
achievement badges so the two views are visually consistent.
- "Top outcome if picked ↓" caption above the right side of each open
elective set so the spec tags are clearly identified as decision-tree
outcomes (not the course's own qualifications).
- Recommended badge moved inline next to the course name (instead of
on a separate row below) to keep button heights stable.
Tests:
- Replace the saturation early-termination test with an exhaustion test
asserting every cell ends with evaluated: true and partial: false.
- Add mode-dependent ordering test (max-count visits Climate Finance
before Corporate Governance in fall3).
- Add evaluated-flag transition test.
- Add throttled progress-event test (>= ~100ms between consecutive
emits).
- Performance smoke updated to a 60s budget for the exhaustive
user-scenario search; 8-open-set typical case completes in ~7s.
Files: solver/decisionTree.ts, solver/priority.ts (already shipped),
data/specColors.ts (new), components/{TopPlans,CourseSelection}.tsx,
state/appState.ts, workers/decisionTree.worker.ts,
__tests__/searchDecisionTree.test.ts, vite.config.ts, CHANGELOG.md,
openspec/changes/decision-tree-exhaustive-search/* (full change spec).
Fixes the bug where a specialization could show "Achievable" while no
per-set ceiling cell surfaces a path to it. Reproduction: pin SP2=Business
of Health & Medical Care, SP4=Foundations of Fintech, SP5=Corporate Finance,
SE1=GIE; rank HCR first. Healthcare showed Achievable but every ceiling
cell excluded HCR.
Root cause: computeCeiling used strict > on count alone, so the first
equal-count combination found won permanently and HCR-including outcomes
were never recorded.
Changes:
- Replace per-(set, choice) computeCeiling loop with a single full-tree
searchDecisionTree DFS. Both the per-set ceiling table and a new ranked
top-K plan list (default K=10) are populated from one enumeration.
- Comparison rule everywhere is (count desc, priority score desc,
deterministic-tiebreak). priorityScore extracted from optimizer.ts
into a shared priority.ts module used by both call sites.
- Heuristic enumeration ordering: select the first reachable ranked spec
as priorityTarget; reorder DFS children at every level so target-
qualifying courses are tried first. High-priority outcomes surface in
early iterations instead of being blocked by less-relevant equal-count
results.
- Bounded search: terminate on saturation (top-K stable for 500
iterations) or hard cap (10000 iterations); set partial=true if cap
hit. Mitigates the worst-case enumeration cost.
- Worker protocol: tagged-union response with topKUpdate, choiceUpdate
(per-cell, replaces per-set setComplete), and allComplete events.
- App state adds topPlans/topPlansPartial slices and an adoptPlan action
that pins a plan's full course assignment in one click. Also fixes
loadState's stale "ranking.length !== 14" check (now uses
SPECIALIZATIONS.length so HCR-era saved state restores correctly).
- New TopPlans component renders the ranked list with adopt buttons,
placed above CourseSelection in the right column.
- 17 new tests in searchDecisionTree.test.ts covering priority scoring,
bounded ranked list, comparison rule, target selection, the user's
reproduction scenario, streaming monotonicity, saturation termination,
and a performance smoke test (< 5s for the 8-open-set case).
- Existing decisionTree.test.ts: one test amended for per-cell streaming
semantics; remaining 3 unchanged and passing.
Apply the J27 (5/6/2026) Stern specialization sheet:
- Add Healthcare (HCR) as the 15th specialization, with HCR cross-listings on
spr2-health-medical, spr3-analytics-ml, sum2-social-media (renamed), and
fall1-managing-change. 10 credits available, no required-course gate.
- Rename sum2-social-media to "Digital Marketing Strategy in Practice";
replace its description with new MSKCC-anchored content; clear instructor
pending confirmation of new lead.
- Switch from delete-and-replace to the previously-unused cancelled flag
(Approach B): mark spr5-customer-insights cancelled, add Managing Growing
Companies back to Summer Set 2 as a cancelled placeholder per the printed
sheet.
- Update data integrity tests: course count 46 -> 47, spec count 14 -> 15;
per-spec "across sets" helper now filters cancelled courses so future
cancellations trigger an obvious assertion failure (BRM 6 -> 5,
MKT 7 -> 6, HCR 4 new).
- Replace hardcoded 14 in optimizer.test.ts with SPECIALIZATIONS.length.
determineStatuses() was marking specs as 'achievable' based solely on
per-specialization upper bounds, ignoring credit sharing with achieved
specs. Now performs an LP feasibility check to verify the spec can
actually be achieved alongside the current achieved set.
- Course info popovers with description, instructors, and specialization
tags; opens on hover (desktop) or tap (mobile) with smart positioning
- Page title and graduation cap favicon in NYU Stern purple
- Desktop layout fits viewport without page-level scrolling
Replace cancelled course in Summer Elective Set 2 with new course
"Innovation and Design" qualifying for Brand Management, Entrepreneurship
and Innovation, Marketing, and Strategy (S2).
- Mark "Managing Growing Companies" as cancelled with visual indicator and solver exclusion
- Prevent selecting duplicate courses across elective sets (e.g., same course in Spring and Summer)
- Add 2.5-credit interval tick marks to specialization progress bars
- Bump version to 1.1.0 with date display in UI header
On mobile, the single-column layout makes it easy to lose context when
scrolling between the specializations and course selection panels. This adds
two floating banners that appear via IntersectionObserver:
- Top banner: summarizes specialization statuses (achieved/achievable/missing/unreachable)
- Bottom banner: shows course selection progress (N/12 selected)
Both slide in/out with CSS transitions and scroll to their respective
sections on tap. Only rendered on mobile viewports (max-width: 639px).
- Replace terse one-line optimization mode descriptions with clearer multi-sentence
explanations of how Maximize Count and Priority Order algorithms behave
- Add skeleton loading placeholders on course buttons while analysis is pending
- Auto-expand achieved specializations to show credit breakdown by default
- Add instructional subtitles to Course Selection and Specializations sections
- Make Clear and Clear All buttons more prominent with visible backgrounds
Replace top-level mutual exclusion banner with dynamic per-course
"Required for ..." labels derived from specialization data. Labels
appear on any course that is a specialization prerequisite, across
all elective sets.
Bill