String Abbreviation Matching

Given two strings, determine if the first string is an abbreviation of the second string. An abbreviation is defined as replacing any non-empty substring of the string with a number, which represents the length of that substring. For example, 'i18n' is an abbreviation of 'internationalization'. You need to support the following examples: "i18n" matches "internationalization", but does not match "interpolation". "f6k" matches "facebook", but does not match "focus". "F2eb2k" matches "Facebook". Please implement a function bool is_match(string abbr, string word), that returns whether the abbreviation matches. Assume strings only contain letters and digits. Example Input 3 "i18n" "internationalization" "f6k" "facebook" "F2eb2k" "Facebook"