# 2 engines: NFA/DFA       RegEx-Art
# FA -> Finite Automation


class Regex:
    """
    Can only support a-z
    """
    def __init__(self):
        self.fsm = []

    def _char_to_int(self, char):
        """
        Returns 0 for a, 1 for b, 2 for c, ... 25 for z
        """
        return ord(char) - 97

    def compile(self, regex_string):
        self.fsm = []
        for char in regex_string:
            next_valid_state = len(self.fsm) + 1
            if char == ".":
                state = [next_valid_state] * 26
            else:
                state = [0] * 26
                state[self._char_to_int(char)] = next_valid_state

            self.fsm.append(state)

    def match(self, text):
        current_state = 0
        for input_char in text:
            current_state = self.fsm[current_state][self._char_to_int(input_char)]
            if current_state == 0:
                return False
        return True


    def __str__(self):
        result = ""
        for row in zip(*self.fsm):
            result += " ".join(str(x) for x in row) + "\n"
        return result