Question

Regular Expressions are the standard way to represent the patterns in the strings. One symbol is ''
which represents all strings that have one or more occurrences of the preceding character. Example:
treza: represent any string that has a string of t's followed by a string of e's followed by a string of a's.
Each of these strings of repeating letters must have atleast one character.
Get the input string and RegEx pattern. Check whether the given string matches with the RegEX
Pattem.
If string matches with the pattern print Matched else print Does not match.
Input Format:​

Answer 1

Answer:

Regular expressions, also known as rational expressions is basically a search pattern.

Explanation:

Such expressions are usually used by string-searching algorithms.

It is a technique developed by American mathematician Matician Stephen Cole Kleene.  

It's a famous concept of theoretical computer science and formal language theory.

Rational expressions are mostly used in search engines, text editors and word processors, and in the lexical analysis.