FA-85734 / Ride-hailing fare and surge pricing / Member archive

Smoothing reads already-smoothed neighbors · case 04

Surge spreads several hops from a hotspot depending on zone name order.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Smooth zone multipliers (tenths): each zone publishes the max of its own raw multiplier and each neighbor's raw multiplier minus 5, clamped to [10, 30]. Adjacency is symmetric even when listed once; neighbors without a raw multiplier are ignored; all reads use raw values, never already-smoothed ones. Return zone -> published multiplier.

Why this case matters

Ride-hailing prices are computed per trip at scale; ordering, unit and boundary slips become systematic over- or under-charging.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: raw neighbor values	`{"A": 20, "B": 30, "C": 30, "D": 25, "E": 25}`	`{"A": 20, "B": 30, "C": 30, "D": 20, "E": 25}`	Failed

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