mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-11-04 11:43:12 +08:00
52 lines
2.2 KiB
HTML
52 lines
2.2 KiB
HTML
<p>Given an integer array <code>data</code> representing the data, return whether it is a valid <strong>UTF-8</strong> encoding.</p>
|
|
|
|
<p>A character in <strong>UTF8</strong> can be from <b>1 to 4 bytes</b> long, subjected to the following rules:</p>
|
|
|
|
<ol>
|
|
<li>For a <strong>1-byte</strong> character, the first bit is a <code>0</code>, followed by its Unicode code.</li>
|
|
<li>For an <strong>n-bytes</strong> character, the first <code>n</code> bits are all one's, the <code>n + 1</code> bit is <code>0</code>, followed by <code>n - 1</code> bytes with the most significant <code>2</code> bits being <code>10</code>.</li>
|
|
</ol>
|
|
|
|
<p>This is how the UTF-8 encoding would work:</p>
|
|
|
|
<pre>
|
|
<code> Char. number range | UTF-8 octet sequence
|
|
(hexadecimal) | (binary)
|
|
--------------------+---------------------------------------------
|
|
0000 0000-0000 007F | 0xxxxxxx
|
|
0000 0080-0000 07FF | 110xxxxx 10xxxxxx
|
|
0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx
|
|
0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx</code>
|
|
</pre>
|
|
|
|
<p><b>Note: </b>The input is an array of integers. Only the <b>least significant 8 bits</b> of each integer is used to store the data. This means each integer represents only 1 byte of data.</p>
|
|
|
|
<p> </p>
|
|
<p><strong>Example 1:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> data = [197,130,1]
|
|
<strong>Output:</strong> true
|
|
<strong>Explanation:</strong> data represents the octet sequence: 11000101 10000010 00000001.
|
|
It is a valid utf-8 encoding for a 2-bytes character followed by a 1-byte character.
|
|
</pre>
|
|
|
|
<p><strong>Example 2:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> data = [235,140,4]
|
|
<strong>Output:</strong> false
|
|
<strong>Explanation:</strong> data represented the octet sequence: 11101011 10001100 00000100.
|
|
The first 3 bits are all one's and the 4th bit is 0 means it is a 3-bytes character.
|
|
The next byte is a continuation byte which starts with 10 and that's correct.
|
|
But the second continuation byte does not start with 10, so it is invalid.
|
|
</pre>
|
|
|
|
<p> </p>
|
|
<p><strong>Constraints:</strong></p>
|
|
|
|
<ul>
|
|
<li><code>1 <= data.length <= 2 * 10<sup>4</sup></code></li>
|
|
<li><code>0 <= data[i] <= 255</code></li>
|
|
</ul>
|