Leetcode 393. UTF-8 Validation

Given an array of integers (bytes), determine if they form a valid UTF‑8 encoding by scanning bytes, counting the leading 1 bits in each leading byte to get the character length (1–4), and verifying that the required number of following bytes exist and each starts with the "10" bit pattern. The core challenge is bitwise inspection and sequence validation to ensure no invalid lengths or malformed continuation bytes occur.