def feed_prng(self, previous_hash, nonce):
hasher = hashlib.sha256()
hasher.update("{0}{1}".format(previous_hash, nonce).encode("ascii"))
seed_hash = hasher.hexdigest()
seed = seed_from_hash(seed_hash)
self.mt = MT64(seed)
def generate_solution(self, previous_hash, nonce):
solution_string = ""
grid = Grid(self.parameters["grid_size"])
seed_hash = self.generate_seed_hash(previous_hash, nonce)
# seed is the last solution hash suffix, else it's 0
prng = coinslib.MT64(coinslib.seed_from_hash(seed_hash))
for i in range(self.parameters["grid_size"]):
# placing extremity walls
grid.walls.append((i, 0))
grid.walls.append((i, self.parameters["grid_size"] - 1))
if i > 0 and i < (self.parameters["grid_size"] - 1):
grid.walls.append((0, i))
grid.walls.append((self.parameters["grid_size"] - 1, i))
start_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
while start_pos in grid.walls:
start_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
end_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
while end_pos in grid.walls or start_pos == end_pos:
end_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
# placing walls
for i in range(self.parameters["nb_blockers"]):
# wall pos (row, col)
block_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
if block_pos != start_pos and block_pos != end_pos and block_pos not in grid.walls:
grid.walls.append(block_pos)
path = []
came_from, cost_so_far = dijkstra_search(grid, start_pos, end_pos)
path = reconstruct_path(came_from, start_pos, end_pos)
for coord in path:
solution_string += "{0}{1}".format(coord[0], coord[1])
if self.debug_output:
self.save_grid(grid, start_pos, end_pos, nonce, path)
hash = self.generate_hash(solution_string)
return Challenge(self.problem_name, nonce, solution_string, hash,
self.parameters)
def generate(self, previous_hash):
# generate a nonce
nonce = random.randint(1000,
10000) # put that into a configuration file
print("Generating {0} problem nonce = {1}".format(
self.problem_name, nonce))
grid = Grid(self.parameters["grid_size"])
seed_hash = self.generate_seed_hash(previous_hash, nonce)
# seed is the last solution hash suffix, else it's 0
prng = coinslib.MT64(coinslib.seed_from_hash(seed_hash))
start_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
end_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
# placing walls
for i in range(self.parameters["nb_blockers"]):
# wall pos (row, col)
block_pos = (prng.extract_number() % self.parameters["grid_size"],
prng.extract_number() % self.parameters["grid_size"])
if block_pos != start_pos and block_pos != end_pos:
grid.walls.append(block_pos)
# starting and ending position
solution_string = ""
try:
came_from, cost_so_far = dijkstra_search(grid, start_pos, end_pos)
path = reconstruct_path(came_from, start_pos, end_pos)
# print(path)
for coord in path:
solution_string += "{0}{1}".format(coord[0], coord[1])
except Exception as e:
print("Shortest Path Challenge error: {0}".format(e))
# No solution exists, so solution string should be empty
hash = self.generate_hash(solution_string)
return Challenge(self.problem_name, nonce, solution_string, hash,
self.parameters)
def generate_solution(self, previous_hash, nonce):
seed_hash = self.generate_seed_hash(previous_hash, nonce)
prng = coinslib.MT64(coinslib.seed_from_hash(seed_hash))
element_list = []
# generate n elements
for i in range(self.parameters["nb_elements"]):
element_list.append(prng.extract_number())
element_list.sort()
solution_string = ""
for i in element_list:
solution_string += "{0}".format(i)
hash = self.generate_hash(solution_string)
return Challenge(self.problem_name, nonce, solution_string, hash,
self.parameters)
