docs = {
    1: "Information retrieval is an essential aspect of search engines.",
    2: "The fiels of information retrieval focuses on algorithms.",
    3: "Search engines use retrieval techniques to improve performance.",
    4: "Deep learning models are used for information retrieval tasks."
}

index = {}

# build index
for i in docs:
    for w in docs[i].lower().replace('.', '').split():
        index.setdefault(w, []).append(i)

# output
q = "retrieval"
print("Documents containing the query 'retrieval':", index.get(q, []))

print("\nInverted Index (Alphabetical Order):")
for w in sorted(index):
    print(w, "->", index[w])

print("\nTotal number of unique terms indexed:", len(index))
print("Documents containing the query 'retrieval':", index.get(q, []))



##RET
docs = {
    1: "information retrieval is important",
    2: "retrieval uses algorithms",
    3: "search uses retrieval"
}

index = {}

# build index
for i in docs:
    for w in docs[i].lower().split():
        if w not in index:
            index[w] = []
        index[w].append(i)

# search
q = "retrieval"
print(index.get(q, []))

