import type { ChartDatapoint } from '../../../core/types/chart-data.js';
/**
 * Returns `[root, ...descendants]` in BFS order (root first, then direct
 * children, then grandchildren, …) using a pre-built `childrenByParentId`
 * map. Callers should build the map once via `buildFlameIndex` and reuse it
 * across renders — this walk is `O(subtree)`, never `O(data)`.
 *
 * A `visited` set guards against cyclic data (a corrupt dataset where a
 * parent id points at one of its own descendants) so the walk terminates.
 * The queue is drained with a head cursor instead of `Array.prototype.shift()`
 * — `.shift()` reindexes the queue and would degrade the walk to `O(n²)`.
 * @internal
 */
export declare function collectSubtree<TData extends ChartDatapoint>(root: TData, rootId: unknown, childrenByParentId: ReadonlyMap<unknown, TData[]>, idAccessor: string): TData[];
//# sourceMappingURL=collect-subtree.d.ts.map