def find_fuel(car):
best = None
best_len = 1e100
best_solver = 'nobody'
for f in [solve_brute_force,
solve_monte_carlo_size2,
#solve_monte_carlo_size3,
#solve_monte_carlo_size6,
solve_LP]:
print f,
fuel = f(car)
if fuel is not None:
assert car.test_on_fuel(fuel), fuel
l = len(fuel_to_stream(fuel))
print 'solved', l
if l < best_len:
best_len = l
best = fuel
best_solver = f
if f == solve_brute_force: # brute force always finds best solution
break
else:
print
who_solved[best_solver] += 1
print 'solvers stats:'
pprint(dict(who_solved))
return best
def find_fuel_stream(car):
if USE_CACHE:
load_cache()
if car.representation in cache:
return cache[car.representation]
fuel = find_fuel(car)
if fuel == None:
return
print(fuel)
suffix = fuel_to_stream(fuel)
load_cache()
cached = cache.get(car.representation)
if cached is None or len(cached) > len(car.representation):
cache[car.representation] = suffix
save_cache()
else:
return cached
return suffix
def solve_monte_carlo(car, size=2, timeout=1.0):
best = None
best_len = 1e100
fuel = [zeros((size,size), dtype=object) for i in range(car.num_tanks)]
start = clock()
for attempt in xrange(10000000):
if clock()-start > timeout:
break
for i in range(car.num_tanks):
for j in range(size):
for k in range(size):
fuel[i][j,k] = randrange(3)
fuel[i][0,0] += 1
if car.test_on_fuel(fuel):
l = len(fuel_to_stream(fuel))
if l < best_len:
best_len = l
best = deepcopy(fuel)
return best
from time import clock
from math import *
from itertools import *
from car import fuel_to_stream, numpy_fuel
print 'prepairing fuels for brute force...',
fuels_to_search = {}
for i in range(1, 7):
n = 40000
limit = int(0.5 + exp(log(n)/i))
fuels = list(product(*[range(1,limit)]*i))
fuel_lens = dict((fuel,len(fuel_to_stream(list(fuel)))) for fuel in fuels)
fuels = sorted(fuels, key = fuel_lens.get)
#print [(f, fuel_lens[f]) for f in fuels[:10]]
fuels_to_search[i] = map(numpy_fuel, fuels)
print 'done'
def solve_brute_force(car):
timeout = 1.0
start = clock()
for fuel in fuels_to_search[car.num_tanks]:
if clock()-start > timeout:
break
if car.test_on_fuel(fuel):
return list(fuel)
