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Sequential plan changes within one cycle: current price tracking · case 02

The second plan change credits the original plan instead of the plan in effect.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Input {start, end, initial price, changes: [[t, price]]}. Changes are ordered by time; at equal times only the last applies. A change outside [start, end) or to the current price is ignored. Each effective change emits a credit line -(current*(end-t)/span) and a debit line new*(end-t)/span, magnitudes half-up, and the new price becomes current. Return the list of line amounts.

Why this case matters

Customers who change plans several times in a cycle must be credited for the plan they actually had at each change.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
regression 0	`[-822, 4110, -279, 562, -192, 238]`	`[-822, 4110, -1397, 562, -386, 238]`	Failed

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