NFA to DFA Conversion

Question

If NFA has n states, then its DFA can have______states in worst case.

Answer 1

2^N  states in maximum case 

Comments

Won't that be less than 2^n.

i.e (2^n) - 1

Answer 2

2^N

Reason;

The next state of nfa coud be any subset of state .

no of subset of states=2^n(as we have 2 choices for each state either we can keep it or not in our subset )