logic: add sugarcane4unary2.py

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Connor Olding 2022-06-08 05:19:13 +02:00
parent a943926fa3
commit a93c4bef65

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logic/sugarcane4unary2.py Normal file
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#!/usr/bin/env python3
# what's the most sugar canes that can be planted with a single water source?
# restriction: all plants must be at the same height.
# restriction: the water source must be at that same height.
# this version is suitable for use with dispensers,
# and requires no additional preparation.
from z0 import Goal, SolverFor, Unary, BitVec, Bool, \
If, IfUnary, Implies, And, Or, Not, Totalizer, sat, unsat, \
binreduce
If, IfBitVec = IfUnary, If
import sys
# configure terminal colors
def esc(x):
return "\x1B[" + str(x) + "m"
color_none = esc(0) + esc(90)
color_plant = esc(102) + esc(30)
color_level_lo = esc(44) + esc(30)
color_level_hi = esc(104) + esc(30)
color_level_zero_lo = esc(100) + esc(34)
color_level_zero_hi = esc(100) + esc(92)
color_reset = esc(0)
def get(el):
if el is None:
return None
elif isinstance(el, Bool):
return model[el.name]
elif isinstance(el, BitVec):
return model[el.name]
elif isinstance(el, Unary):
return model[el.name].bit_length()
else:
assert False, el
return 0
def render(level, plant, block):
if plant is None:
return color_none + ":"
if level is None:
return color_none + ";" # erroneous
if plant == 1:
return color_plant + "X"
if block == 1: # upper
if level == 0:
return color_level_zero_hi + "O"
else:
return color_level_hi + str(level)
else: # lower
if level == 0:
return color_level_zero_lo + "0"
else:
return color_level_lo + str(level)
def render_short(short):
if short is None:
return color_none + ":"
if short == 0:
return color_level_zero_lo + "0"
else:
return color_level_lo + str(short)
###
start_level = 8
size = 1 + 2 * (start_level - 2 + # upper
start_level + 1) # lower
halfsize = size // 2
if 1:
symmetry = 4 # rotational
cross_heuristic = True
no_preparation = True
previous = 200 # best: 240 without preparation, 260 with.
level_max = start_level
max_upper = start_level - 1
else:
symmetry = 4
cross_heuristic = True
no_preparation = False
previous = 0
level_max = start_level #+ 1
max_upper = 1
def mandist(x, y):
return abs(x - halfsize) + abs(y - halfsize)
def make2d(f, w=size, h=size):
return [[f(x, y) for x in range(w)] for y in range(h)]
# generate the unobstructed diamond shape by manhattan distances.
usable = make2d(lambda x, y: mandist(x, y) <= halfsize)
usables = sum(1 if t else 0 for row in usable for t in row)
plant_len = usables.bit_length()
def makeuse(f, usable=usable):
return make2d(lambda x, y: f(x, y) if usable[y][x] else None)
# since the water level is strictly decreasing,
# we can skip generating equations for blocks where usable[y][x] == False.
xy_fmt = "{:02X}{:02X}" if symmetry == 4 else "x{:02}y{:02}"
xyi_fmt = "{:02X}{:02X}u{:01X}" if symmetry == 4 else "x{:02}y{:02}u{:01X}"
levels = makeuse(lambda x, y: Unary("L" + xy_fmt.format(x, y), level_max))
blocks = makeuse(lambda x, y: Bool("B" + xy_fmt.format(x, y)))
plants = makeuse(lambda x, y: Bool("P" + xy_fmt.format(x, y)))
# find the shortest path down to the lower level by flowing backwards.
# this needs only a smaller section than the previous variables.
short_usable = makeuse(lambda x, y: (no_preparation and
mandist(x, y) <= start_level))
shorts = makeuse(lambda x, y: Unary("S" + xy_fmt.format(x, y), level_max),
short_usable)
arrays = (levels, blocks, plants, shorts)
if symmetry == 1:
pass
elif symmetry == 2:
for array in arrays:
for y_a in range(halfsize + 1):
y_b = size - y_a - 1
for x_a in range(size):
x_b = size - x_a - 1
array[y_b][x_b] = array[y_a][x_a]
elif symmetry == 4:
middle = halfsize + 1
for array in arrays:
for y in range(middle):
for x in range(middle):
# bottom right corner:
# equivalent to mirroring both axes.
array[size - y - 1][size - x - 1] = array[y][x]
# bottom left corner:
# as x increases, y decreases.
# as y increases, x increases.
array[size - x - 1][y] = array[y][x]
# top right corner:
# as x increases, y increases.
# as y increases, x decreases.
array[x][size - y - 1] = array[y][x]
else:
raise Exception(f"unsupported value of symmetry: {symmetry}")
def check(x, y):
return x >= 0 and y >= 0 and x < size and y < size and usable[y][x]
def maybe(x, y):
return (levels[y][x], blocks[y][x], shorts[y][x]) if check(x, y) else None
def xyiter(width, height):
for y in range(height):
for x in range(width):
yield x, y
###
g = Goal()
if symmetry == 1:
sym_width, sym_height = size, size
elif symmetry == 2:
sym_width, sym_height = size, (size + 1) // 2
elif symmetry == 4:
sym_width, sym_height = (size + 1) // 2, (size + 1) // 2
plant_pairs = []
for x, y in xyiter(sym_width, sym_height):
if not usable[y][x]:
continue
level_var = levels[y][x]
block_var = blocks[y][x]
plant_var = plants[y][x]
short_var = shorts[y][x]
for var in (level_var, short_var):
if var is None:
continue
# bound the water levels.
g.add(var <= start_level)
distance = mandist(x, y)
# the center block is the water source block.
centered = distance == 0
# plants must be on blocks.
g.add(Implies(plant_var, block_var))
# plants cannot be placed in water!
g.add(Implies(plant_var, level_var == 0))
if cross_heuristic and (x == halfsize or y == halfsize):
# 8765432 876543210
# 0123456 789ABCDEF
step_kink = max_upper
if distance < step_kink:
g.add(level_var == start_level - distance)
g.add(block_var == True)
g.add(plant_var == False)
elif distance == start_level + step_kink:
g.add(level_var == 0)
g.add(block_var == True)
g.add(plant_var == True)
else:
g.add(level_var == max(start_level + step_kink - distance, 0))
g.add(block_var == False)
g.add(plant_var == False)
elif centered:
# configure the water source.
g.add(level_var == start_level)
g.add(block_var == True)
g.add(plant_var == False)
# take account for symmetry.
plant_worth = 1
if symmetry == 2:
plant_worth = 2 if y != halfsize else 1
elif symmetry == 4:
if x != halfsize:
plant_worth *= 2
if y != halfsize:
plant_worth *= 2
plant_pairs.append((plant_var, plant_worth))
# gather information on cardinal directions.
neighbors = [maybe(x - 1, y), # west, "left"
maybe(x + 1, y), # east, "right"
maybe(x, y - 1), # north, "up"
maybe(x, y + 1)] # south, "down"
neighbors = [n for n in neighbors if n is not None]
# gather information about neighboring cells.
max_level_hi = 0
max_level_lo = 0
max_short = 0
for n_level, n_block, n_short in neighbors:
max_level_hi = Unary.max(max_level_hi, If(n_block, n_level, 0))
max_level_lo = Unary.max(max_level_lo, If(n_block, 0, n_level))
if n_short is not None:
max_short = Unary.max(max_short, n_short)
# some convenience...
upper = block_var
lower = Not(block_var)
any_level = level_var != 0
#assert max_upper == start_level - 1, "unimplemented (FIXME)"
if max_upper < start_level:
g.add(Implies(And(upper, any_level), level_var > start_level - max_upper))
# this isn't necessary, but might assist the solver:
# NOTE: should probably include max_level_lo > 0 as well.
# NOTE: this turns out to be necessary for strictly correct no_preparation.
g.add(Implies(And(upper, Not(any_level)), plant_var))
# plants must be placed next to water alongside and below its block.
g.add(Implies(plant_var, max_level_lo != 0))
if not no_preparation:
short = True
elif short_var is None:
short = False
else:
# find the shortest path down from the upper level.
# annoyingly, this is how water flows in minecraft.
# the usual flow, but backwards.
g.add(Implies(And(upper, max_short != 0),
short_var == max_short - 1))
g.add(Implies(lower, short_var == start_level))
source_short_var = shorts[halfsize][halfsize]
short = short_var == source_short_var + distance
# trying some alternative definitions:
if not centered:
g.add(Implies(upper,
level_var == If(And(short, max_level_hi != 0),
max_level_hi - 1, 0)))
g.add(Implies(lower,
level_var == If(max_level_hi != 0, start_level,
If(max_level_lo != 0,
max_level_lo - 1, 0))))
if 1:
plant_sum = BitVec("Plants", plant_len, 0)
plant_scores = [IfBitVec(var, worth, 0, plant_len) for var, worth in plant_pairs]
#plant_sum = sum(plant_scores)
plant_sum = binreduce(plant_scores, lambda a, b: a + b)
else:
plant_scores = sum(([var] * worth for var, worth in plant_pairs), [])
plant_sum = Totalizer(plant_scores)
# TODO: optimal(?) sum reduction (assuming inputs are 1-bit) would be:
# A = 1 + 1 + 1 = 3 (2 bits)
# B = A + A + 1 = 3 + 3 + 1 = 7 (3 bits)
# C = B + B + 1 = 7 + 7 + 1 = 15 (4 bits)
# etc.
s = SolverFor("QF_BV") # Quantifier-Free Bit-Vectors
s.add(g)
satisfiable = s.check()
print("check:", satisfiable)
sys.stdout.flush()
if len(sys.argv) > 1 and sys.argv[1] == "check":
sys.exit(0)
while satisfiable == sat:
#satisfiable = s.check(plant_sum > previous)
g.add(plant_sum > previous)
satisfiable = s.check()
print("check:", satisfiable)
if satisfiable != sat:
break
model = s.model()
#previous = model['Plants'] # doesn't work since this is *before* summing
previous = sum(worth if model[var.name] else 0
for var, worth in plant_pairs)
print("plants:", previous)
water = sum(1 if var is not None and model[var.name] > 0 else 0 for row in levels for var in row)
print("water: ", water)
#print(model)
#for k, v in model.items():
# if v != 0:
# print(k, v)
lines = ""
for rows in zip(levels, plants, blocks, shorts):
all_row = [[get(el) for el in row] for row in rows]
lines += "".join(render(level, plant, block)
for level, plant, block, _ in zip(*all_row))
if no_preparation: # shortest distance debugging
lines += " "
lines += "".join(render_short(short)
for _, _, _, short in zip(*all_row))
lines += color_reset + "\n"
print(lines)
sys.stdout.flush()