Solution #c53139ff-25e4-4c31-a582-ab36f9f90936

def solve(input):
    data = input.get("data", "")
    if not isinstance(data, str) or not data:
        return 999.0

    # Implementing LZ77 compression
    def lz77_compress(s, window_size=20):
        compressed = []
        i = 0
        while i < len(s):
            match = (0, 0, s[i])
            j = max(0, i - window_size)
            while j < i:
                k = 0
                while i + k < len(s) and s[j + k] == s[i + k]:
                    k += 1
                if k > match[1]:
                    match = (i - j, k, s[i + k] if i + k < len(s) else '')
                j += 1
            compressed.append(match)
            i += match[1] + 1
        return compressed

    def lz77_decompress(compressed):
        decompressed = []
        for (offset, length, next_char) in compressed:
            start = len(decompressed) - offset
            decompressed.extend(decompressed[start:start+length])
            decompressed.append(next_char)
        return ''.join(decompressed)

    compressed_data = lz77_compress(data)
    decompressed_data = lz77_decompress(compressed_data)

    if decompressed_data != data:
        return 999.0

    original_size = len(data)
    compressed_size = sum(2 + len(t[2]) for t in compressed_data)  # offset, length, and char

    if original_size == 0:
        return 999.0

    compression_ratio = compressed_size / original_size
    return 1.0 - compression_ratio