Validate abbreviations and brackets

The coding round included two short implementation problems: 1. Abbreviation validation Given a lowercase word `word` and a string `abbr`, determine whether `abbr` is a valid abbreviation of `word`. - Letters in `abbr` must match the corresponding letters in `word`. - A positive integer in `abbr` means skipping that many characters in `word`. - Numbers cannot have leading zeros. - The abbreviation is valid only if it consumes the entire word exactly. Example: - `word = "internationalization"`, `abbr = "i12iz4n"` -> `true` - `word = "apple"`, `abbr = "a2e"` -> `false` 2. Balanced bracket validation Given a string `s` containing only the characters `(`, `)`, `[`, `]`, `{`, and `}`, return whether the brackets are balanced. - Every opening bracket must be closed by the same type of bracket. - Brackets must be closed in the correct order. - An empty string is considered valid. Example: - `s = "()[]{}"` -> `true` - `s = "([)]"` -> `false`