Count Strings Problem: Hacker Rank

Given a regular expression and an integer, , count how many strings of length are recognized by it.

Sources Used for reference: https://www.cs.york.ac.uk/fp/lsa/lectures/REToC.pdf https://en.wikipedia.org/wiki/Nondeterministic_finite_automaton https://en.wikipedia.org/wiki/Powerset_construction And a bit of insipiration from: https://github.com/kennyledet/Algorithm-Implementations/blob/master/Thompsons_Construction_Algorithm/C%2B%2B/AlexMathew/RE_to_NFA.cpp

Steps:

1. Parsing ---> converting Infix regex to Postfix

2. Postfix Expression---> NFA (Thompson Algorithm)

3. NFA --> DFA (Subset Construction Algorithm)

4)DFA-->Adjacency MAtrix