# Retrieved from: http://en.literateprograms.org/Sierpinski_triangle_(Python)?oldid=9930
##A one-dimensional cellular automaton is a linear space of cells,
##each of which has a state. The automaton changes in discrete time
##steps called generations. In each generation the state of each cell is
##decided according to a set of rules that is based on the states of
##neighboring cells. In the case of one-dimensional cellular automaton
##each cell has its state decided by considering three cells, itself and
##its left and right neighboring cells. Neighbouring the first and last
##cells of the space, we will assume virtual cells that are always in a
##default state. The Sierpinski cellular automaton has two states,
##Empty and Full. The only rule states that a cell will be set to Full
##if and only if of the three states considered exactly one or two are
##Full.

#Simpler statement: If you look like your 2 neighbors (L & R) you are dead next.

AUTOMATA_SIZE = 64
#Put 0's everywhere in row 0, except for the center 1
#0000000000000000000000000100000000000000000000000000

init_states = [0]*(AUTOMATA_SIZE/2 - 1) + [1] + [0]*(AUTOMATA_SIZE/2)

rules = {(0, 0, 0):0, 
         (0, 0, 1):1,
         (0, 1, 0):1,
         (0, 1, 1):1,
         (1, 0, 0):1,
         (1, 0, 1):1,
         (1, 1, 0):1,
         (1, 1, 1):0}

#So next generation will be:
#0000000000000000000000001110000000000000000000000000

def apply_rules(states):
    width = len(states)
    new_states = states[:]
    new_states[0] = rules[(0, states[0], states[1])]
    new_states[width - 1] = rules[(states[width - 2], states[width - 1], 0)]

    for i in range(1, width - 2):
        new_states[i] = rules[(states[i - 1], states[i], states[i + 1])]
    return new_states


def state_to_char(state):
    if state==0: 
        return '0'  #replace with empty space ' ' to remove the 0's
    else: 
        return '1'  #replace with some other symbol like @ , * or #
        
def states_to_string(states):
    return ''.join(map(state_to_char, states))
    
def run_and_display(n_gens):
    states = init_states
    for i in range(n_gens):
        print states_to_string(states)
        states = apply_rules(states)

if __name__ == "__main__":
    run_and_display(32)