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@juanplopes juanplopes/
Last active Aug 13, 2019

What would you like to do?
simple dfa in python
class Automaton:
def __init__(self, nstates):
self.transitions = [{} for i in range(nstates)]
self.accept_states = [False] * nstates
def register(self, source_state, char, target_state):
self.transitions[source_state][char] = target_state
def register_accept(self, state):
self.accept_states[state] = True
def accept(self, input):
state = 0
for char in input:
state = self.transitions[state][char]
return self.accept_states[state]
except KeyError:
return False
#to recognize "[abc]x*"
--- --
/ b \ / |x
\ c /
automaton = Automaton(2)
automaton.register(0, 'a', 1)
automaton.register(0, 'b', 1)
automaton.register(0, 'c', 1)
automaton.register(1, 'x', 1)
print automaton.accept('ax') #True
print automaton.accept('bxxx') #True
print automaton.accept('abxxx') #False
print automaton.accept('dx') #False
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