题目：

题解：

const mask1, mask2 = 1 << 7, 1<<7 | 1<<6func getBytes(num int) int {if num&mask1 == 0 {return 1}n := 0for mask := mask1; num&mask != 0; mask >>= 1 {n++if n > 4 {return -1}}if n >= 2 {return n}return -1
}func validUtf8(data []int) bool {for index, m := 0, len(data); index < m; {n := getBytes(data[index])if n < 0 || index+n > m {return false}for _, ch := range data[index+1 : index+n] {if ch&mask2 != mask1 {return false}}index += n}return true
}