You have to write a function checkRegex() which takes two strings as input, one string represents a regex expression and other is an input string to match with the regex expression passed as the other parameter. Return true if it matches, else false.

I found this question on one of the forum

Regex may contain characters ‘a-z’, ‘.’ and ‘*’ where ‘.’ matches any character and ‘*’ means 0 or more occurrences of the previous character preceding it.

Examples:
1) a*b matches b,ab,aab
2) a.b matches aab, abb, acb,…, azb
3) .* matches all the valid strings formed by using the lowercase letters


Status: Solved

Algorithm:Recursion



Time Complexity O(2^n)
Space Complexity O(1)