my solutions for advent of code 2022
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2 years ago
import copy
from queue import PriorityQueue
MAX_PRIO = ord('z') - ord('a')
log_this_is_n = 0
n_solutions = 0
q = PriorityQueue()
point_cost = {}
def log_every_n(message):
global log_this_is_n
log_this_is_n = (log_this_is_n + 1) % 100000
if log_this_is_n == 0:
print(message)
class PossiblePath:
def __init__(self, y, x, visited):
self.x = x
self.y = y
self.visited = tuple(visited)
def __lt__(self, other):
return (len(self.visited) < len(other.visited) or
self.x < other.x or
self.y < other.y)
def MakeCandidate(x, y, visited, value_diff):
if (y, x) in point_cost and point_cost[(y, x)] <= len(visited):
return
point_cost[(y, x)] = len(visited)
prio_valuediff = value_diff * -1
prio_distance = (max(End[0], x) - min(End[0], x)) + (max(End[1], y) - min(End[1], y))
prio_lettervalue = MAX_PRIO - grid[y][x]
prio_pathlen = (gridX * gridY) - len(visited)
path = PossiblePath(y, x, visited)
q.put((prio_valuediff, prio_distance, path))
def findPath():
global fewestSteps
global n_solutions
while not q.empty():
_, _, path = q.get()
if (path.y, path.x) in point_cost and point_cost[(path.y, path.x)] < len(path.visited):
# We already have a better path to the current point.
continue
log_every_n('Inspecting: %dx%d, visited %d points, %d solutions' % (path.x, path.y, len(path.visited), n_solutions))
visited = list(path.visited)
if (path.y, path.x) in visited:
continue
visited.append((path.y, path.x))
if (not (fewestSteps == None)) and (len(visited) - 1 >= fewestSteps):
continue
if [path.x, path.y] == End:
print('Visited: ', visited)
print('Steps: ', len(visited) - 1)
fewestSteps = len(visited) - 1
n_solutions += 1
continue
if path.x > 0:
if grid[path.y][path.x - 1] <= grid[path.y][path.x] + 1:
valDiff = grid[path.y][path.x - 1] - grid[path.y][path.x]
MakeCandidate(path.x - 1, path.y, visited, valDiff)
if path.x < gridX:
if grid[path.y][path.x + 1] <= grid[path.y][path.x] + 1:
valDiff = grid[path.y][path.x + 1] - grid[path.y][path.x]
MakeCandidate(path.x + 1, path.y, visited, valDiff)
if path.y > 0:
if grid[path.y - 1][path.x] <= grid[path.y][path.x] + 1:
valDiff = grid[path.y - 1][path.x] - grid[path.y][path.x]
MakeCandidate(path.x, path.y - 1, visited, valDiff)
if path.y < gridY:
if grid[path.y + 1][path.x] <= grid[path.y][path.x] + 1:
valDiff = grid[path.y + 1][path.x] - grid[path.y][path.x]
MakeCandidate(path.x, path.y + 1, visited, valDiff)
with open('input12.txt','r') as f:
inp = f.read().splitlines(keepends=False)
grid = []
fewestSteps = None
for i in range(len(inp)):
grid.append([])
for j in range(len(inp[i])):
if inp[i][j] == 'S':
Start = [j, i]
grid[i].append(0)
elif inp[i][j] == 'E':
End = [j, i]
grid[i].append(ord('z') - ord('a'))
else:
grid[i].append(ord(inp[i][j])-ord('a'))
gridX = len(grid[0]) - 1
gridY = len(grid) - 1
_x = Start[0]
_y = Start[1]
if Start[0] > 0:
if grid[_y][_x - 1] <= 1:
MakeCandidate(_x - 1, _y, [(_y, _x)], grid[_y][_x - 1])
if Start[0] < gridX:
if grid[_y][_x + 1] <= 1:
MakeCandidate(_x + 1, _y, [(_y, _x)], grid[_y][_x + 1])
if Start[1] > 0:
if grid[_y - 1][_x] <= 1:
MakeCandidate(_x, _y - 1, [(_y, _x)], grid[_y - 1][_x])
if Start[1] < gridY:
if grid[_y + 1][_x] <= 1:
MakeCandidate(_x, _y + 1, [(_y, _x)], grid[_y + 1][_x])
findPath()
print(fewestSteps)
#for x in grid:
# tempa = ''
# for y in x:
# tempa += chr(y + 97)
# print(tempa)