5 marks: def cosine(a,b):
    dot = sum(x*y for x,y in zip(a,b))
    na = sqrt(sum(x*x for x in a))
    nb = sqrt(sum(y*y for y in b))
    return dot/(na*nb)(Marks: correct dot product and normalisation.)

5分:def cosine(a, b):
    dot = sum(x*y for x, y in zip(a, b))
    na = sqrt(sum(x*x for x in a))
    nb = sqrt(sum(y*y for y in b))
    return dot / (na*nb)
(評分依據:內積與正規化計算正確。)

5 marks: def retrieve(q,docs,k):
    scored=[(cosine(q,d['emb']),d) for d in docs]
    scored.sort(reverse=True, key=lambda t:t[0])
    return [d for _,d in scored[:k]](Marks: scores all docs, sorts, returns k.)

5分:def retrieve(q, docs, k):
    scored = [(cosine(q, d['emb']), d) for d in docs]
    scored.sort(reverse=True, key=lambda t: t[0])
    return [d for _, d in scored[:k]]
(評分依據:對所有文件計分、排序,並回傳前k筆。)

6 marks: def answer(query,q_emb,docs):
    top = retrieve(q_emb,docs,3)
    context = "\n".join(f"[{i}] {d['text']}" for i,d in enumerate(top))
    prompt = ("Answer using ONLY the sources; cite [n].\n"
              f"Sources:\n{context}\nQ: {query}")
    return generate(prompt)(Marks: uses retrieve, builds grounded prompt, instructs citation / only-context.)

6分:def answer(query, q_emb, docs):
    top = retrieve(q_emb, docs, 3)
    context = "\n".join(f"[{i}] {d['text']}" for i, d in enumerate(top))
    prompt = ("請只根據以下資料來源作答,並標註引用編號[n]。\n"
              f"資料來源:\n{context}\n問題:{query}")
    return generate(prompt)
(評分依據:有使用retrieve、建構出有依據的提示詞、並要求引用出處/只能使用提供的內容作答。)