Incremental UTF-8 Decoding

Problem

Decode a stream of UTF-8 byte chunks without corrupting characters split across chunks. Return one string per input chunk, containing only characters that become complete at that chunk. Incomplete bytes must be buffered for the next chunk.

The concatenation of all chunks is valid complete UTF-8. Empty chunks produce empty strings; no chunks returns []. Do not emit replacement characters.

def decode_utf8_chunks(chunks):

Constraints

• chunks contains 0..32 lists of integers in [0,255]; at most 256 bytes total.
• The complete byte stream is valid UTF-8, even if individual chunks are not.
• Inputs satisfy these constraints; invalid-input handling is not graded. Use only Python standard library and NumPy.

Examples

Arguments: [
  [
    [
      195
    ],
    [
      169
    ]
  ]
]
Expected result: [
  "",
  "é"
]

Arguments: [
  [
    [
      72,
      105
    ],
    [],
    [
      33
    ]
  ]
]
Expected result: [
  "Hi",
  "",
  "!"
]