Solution #29bbc470-d5f9-4aa4-88f5-8de8fa768be2

1def solve(input):
2    text = input.get("text", "")
3    n = len(text)
4    if not n:
5        return {"encoded_length": 0, "decoded": ""}
6
7    items = tuple(map(lambda kv: kv[1], __import__("collections").Counter(text).items()))
8    if len(items) == 1:
9        return {"encoded_length": n, "decoded": text}
10
11    heapq = __import__("heapq")
12    h = list(items)
13    heapq.heapify(h)
14
15    merged = []
16    append = merged.append
17    pop = heapq.heappop
18    push = heapq.heappush
19
20    def rec(k):
21        return None if k == 0 else (
22            lambda a=pop(h), b=pop(h), s=None: (
23                push(h, a + b),
24                append(a + b),
25                rec(k - 1)
26            )
27        )()
28
29    rec(len(h) - 1)
30    return {"encoded_length": sum(merged), "decoded": text}

1def solve(input):
2    text = input.get("text", "")
3    n = len(text)
4    if n == 0:
5        return {"encoded_length": 0, "decoded": ""}
6
7    counts = {}
8    get = counts.get
9    for ch in text:
10        counts[ch] = get(ch, 0) + 1
11
12    freqs = list(counts.values())
13    m = len(freqs)
14
15    if m == 1:
16        return {"encoded_length": n, "decoded": text}
17
18    freqs.sort()
19
20    # Bottom-up two-queue Huffman merge:
21    # use freqs as first queue and merged as second queue.
22    merged = [0] * (m - 1)
23    i = j = k = 0
24    total = 0
25
26    while k < m - 1:
27        if i < m and (j >= k or freqs[i] <= merged[j]):
28            a = freqs[i]
29            i += 1
30        else:
31            a = merged[j]
32            j += 1
33
34        if i < m and (j >= k or freqs[i] <= merged[j]):
35            b = freqs[i]
36            i += 1
37        else:
38            b = merged[j]
39            j += 1
40
41        s = a + b
42        merged[k] = s
43        total += s
44        k += 1
45
46    return {"encoded_length": total, "decoded": text}