Automata Theory Questions
A regular expression with backreferences is a pattern that allows referencing previously matched subpatterns within the same regular expression. It enables capturing and reusing specific portions of a matched string. Backreferences are denoted by a backslash followed by a number or a name, representing the order or name of the capturing group. When the regular expression is matched, the backreference will match the same text as the captured group. This feature is particularly useful for tasks such as finding repeated patterns or validating input based on previously matched content.