393. UTF-8 Validation Medium

1/**
2 * [393] UTF-8 Validation
3 *
4 * Given an integer array data representing the data, return whether it is a valid UTF-8 encoding (i.e. it translates to a sequence of valid UTF-8 encoded characters).
5 * A character in UTF8 can be from 1 to 4 bytes long, subjected to the following rules:
6 * <ol>
7 * 	For a 1-byte character, the first bit is a 0, followed by its Unicode code.
8 * 	For an n-bytes character, the first n bits are all one's, the n + 1 bit is 0, followed by n - 1 bytes with the most significant 2 bits being 10.
9 * </ol>
10 * This is how the UTF-8 encoding would work:
11 * 
12 *      Number of Bytes   |        UTF-8 Octet Sequence
13 *                        |              (binary)
14 *    --------------------+-----------------------------------------
15 *             1          |   0xxxxxxx
16 *             2          |   110xxxxx 10xxxxxx
17 *             3          |   1110xxxx 10xxxxxx 10xxxxxx
18 *             4          |   11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
19 * 
20 * x denotes a bit in the binary form of a byte that may be either 0 or 1.
21 * Note: The input is an array of integers. Only the least significant 8 bits of each integer is used to store the data. This means each integer represents only 1 byte of data.
22 *  
23 * Example 1:
24 * 
25 * Input: data = [197,130,1]
26 * Output: true
27 * Explanation: data represents the octet sequence: 11000101 10000010 00000001.
28 * It is a valid utf-8 encoding for a 2-bytes character followed by a 1-byte character.
29 * 
30 * Example 2:
31 * 
32 * Input: data = [235,140,4]
33 * Output: false
34 * Explanation: data represented the octet sequence: 11101011 10001100 00000100.
35 * The first 3 bits are all one's and the 4th bit is 0 means it is a 3-bytes character.
36 * The next byte is a continuation byte which starts with 10 and that's correct.
37 * But the second continuation byte does not start with 10, so it is invalid.
38 * 
39 *  
40 * Constraints:
41 * 
42 * 	1 <= data.length <= 2 * 10^4
43 * 	0 <= data[i] <= 255
44 * 
45 */
46pub struct Solution {}
47
48// problem: https://leetcode.com/problems/utf-8-validation/
49// discuss: https://leetcode.com/problems/utf-8-validation/discuss/?currentPage=1&orderBy=most_votes&query=
50
51// submission codes start here
52
53impl Solution {
54    pub fn valid_utf8(data: Vec<i32>) -> bool {
55        false
56    }
57}
58
59// submission codes end
60
61#[cfg(test)]
62mod tests {
63    use super::*;
64
65    #[test]
66    fn test_393() {
67    }
68}
69