Finite State Machines (Automatas) in C++

accepts.cpp

	bool accepts(string str)
	{
		return contains(F,delta_hat(q0,str));
	}

contains.cpp

template<typename T>
bool contains(const set<T>& all,const T& elem)
{
	return all.find(elem) != all.end();
}

delta1.cpp

unsigned delta1(unsigned state, char input)
{
	if(state==0)
		if (input=='1')
			return 0;
		else // input=='0'
			return 1;
	else {// state==1
			return 1;
	}
}

delta_hat.cpp

	State_T delta_hat(State_T q, string str)
	{
		State_T theState=q;
		for(char c : str) {
			cout << "at " << theState << " seeing " << c ;
			theState=delta(theState,c);
			cout << " went to " << theState << endl;
		}
		return theState;
	}

dfa.cpp

template<typename State_T>
struct DFA {
	set<State_T> Q,F; // all states, and accepting states
	State_T q0; // the starting state
	set<char> sigma;
	std::function<State_T(State_T, char)> delta;
...
};

main.cpp

int main(int argc, char* argv[])
{
	set<unsigned> Qs {0,1};
	set<unsigned> Fs {1};
	set<char> Sigma {'0','1'};
	
	DFA<unsigned> dfa1=DFA<unsigned>(Qs,Fs,0,Sigma,delta1);
	
	int from=atoi(argv[1]);
	string str(argv[2]);
	cout << dfa1.delta_hat(from,argv[2]) << endl;
	cout << boolalpha << dfa1.accepts(str) << endl;
}