2322.py

infile=0
# p1: 895 hi 
# p2: 1200 lo
Blocs = [] # a bloc is a tuple of tuple-pairs ((x,y,z),(x2,y2,z2))
with open('22.' + str(infile)) as file:
    for line in file:
        L, R = line.split('~')
        S = tuple([ int(_) for _ in L.split(',') ])
        E = tuple([ int(_) for _ in R.split(',') ])
        Blocs.append((S,E))
#for b in Blocs:print(b)
Beams = []
seen = set()
for bloc in Blocs:
    Beam = []
    s,e = bloc
    a, b, c = s
    aa,bb,cc = e    # vertical bloc
    if a == aa and b == bb:
        for _ in range(c, cc + 1):
            Beam.append( (a, b, _) )
    # X beam
    if b == bb and c == cc:
        for _ in range(a, aa + 1):
            Beam.append( (_, b, c) )
    # vertical bloc
    if c == cc and a == aa:
        for _ in range(b, bb + 1):
            Beam.append( (a, _, c) )
    for _ in Beam:
        seen.add( _ )
    Beams.append(Beam)

while True:
    moved = False
    for i, beam in enumerate(Beams) :
        stuck = False
        for (a, b, c) in beam:
            if c == 1: # on the ground
                stuck = True
            below = (a, b, c - 1) # possible if we check it bef. for loop
            if below not in beam and below in seen: # met another beam
                stuck = True
        if stuck:
            continue
        Beams[ i ] = [ (a, b, c - 1) for (a, b, c) in beam ]
        for (a, b, c) in beam:
            seen.discard( (a, b, c) )
            seen.add( (a, b, c - 1) )
        moved = True
    if not moved:
        break
print(seen, len(seen))


# Both parts

from copy import deepcopy

def p1solver(S, B):
    seen = deepcopy(S)
    Beams = deepcopy(B)
    res = 0
    for i, beam in enumerate(Beams) :
        for layer in beam:
            # suppose this one beam is not there
            seen.discard( layer )
        moved = False
        for k, other in enumerate(Beams):
            if k == i: continue
            stuck = False
            for layer in other:
                a, b, c = layer
                below = ( a, b, c - 1 )
                if below not in other and below in seen or c == 1:
                    stuck = True
            if not stuck:
                moved = True
        res += not moved
        for layer in beam:
            # end sim, added beam back
            seen.add( layer )
    return res


# Part 2

def p2solver(seen, Beams):

    saved_seen = deepcopy( seen )
    saved_beams = deepcopy( Beams )

    res = 0
    for i, beam in enumerate(Beams) :
        falling = set()
        seen = deepcopy( saved_seen )
        Beams = deepcopy( saved_beams )
        for layer in beam:
            # suppose this one beam is not there
            seen.discard( layer )
        while True:
            moved = False
            for k, other in enumerate(Beams):
                if k == i: continue
                stuck = False
                for layer in other:
                    a, b, c = layer
                    below = ( a, b, c - 1 )
                    if below not in other and below in seen or c == 1:
                        stuck = True
                if not stuck:
                    falling.add( k )
                    Beams[ k ] = [ (a, b, c - 1) for (a, b, c) in other ]
                    for (a, b, c) in other:
                        seen.discard( (a, b, c) )
                        seen.add( (a, b, c - 1) )
                    moved = True
            if not moved:
                break
        res += len(falling)
    return res

p1 = p1solver( seen, Beams )
print('part 1:', p1)

p2 = p2solver( seen, Beams )
print('part 2:', p2)

assert(p1 in [ 405, 5 ])
assert(p2 in [ 61297, 7 ])