This commit introduces two functions in the string algorithms: 'find_and_replace' and 'find_and_replace_regex'. The first function finds all occurrences of a given substring in a string and replaces them with a new substring. The second function does the same but supports regular expression patterns. + Added missing lib in hash_table class
This commit introduces two functions in the string algorithms: 'find_and_replace' and 'find_and_replace_regex'. The first function finds all occurrences of a given substring in a string and replaces them with a new substring. The second function does the same but supports regular expression patterns. + Added missing lib in hash_table class