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

1. 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