Retrieval & Ranking · Easy

Top-K Heap

Select highest-scoring items efficiently with deterministic heap ordering.

Task

Implement top_k_heap(scores: list[float], k: int) -> list[int]. Return the indices of the highest-scoring items by maintaining a bounded min-heap.

scores contains finite numeric values and k is a non-negative integer.
Return at most min(k, len(scores)) original indices.
Rank selected indices by descending score.
When scores tie, rank the smaller original index first.
Use a heap containing at most k candidates while scanning scores; do not sort the entire input.
After selection, sort only the retained candidates into the required output order.
Return an empty list when k is zero or scores is empty.
When k is at least the input length, return every index in deterministic rank order.
Do not mutate scores.

top_k_heap([0.4, 0.9, 0.9, 0.2, 0.7], 3)
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