This problem was asked by Facebook.
Given a string of round, curly, and square open and closing brackets, return whether the brackets are balanced (well-formed).
For example, given the string ([])[]({}), you should return true.
Given the string ([)] or (((), you should return false.
This problem was asked by Google.
UTF-8 is a character encoding that maps each symbol to one, two, three, or four bytes.
For example, the Euro sign, €, corresponds to the three bytes 11100010 10000010 10101100. The rules for mapping characters are as follows:
For a single-byte character, the first bit must be zero. For an n-byte character, the first byte starts with n ones and a zero. The other n - 1 bytes all start with 10. Visually, this can be represented as follows.
| Bytes | Byte format |
|---|---|
| 1 | 0xxxxxxx |
| 2 | 110xxxxx 10xxxxxx |
| 3 | 1110xxxx 10xxxxxx 10xxxxxx |
| 4 | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx |
| Write a program that takes in an array of integers representing byte values, and returns whether it is a valid UTF-8 encoding. |