adventofcode2024/day18/sol.py

48 lines
1.0 KiB
Python

from collections import defaultdict
import astar
def parse(file):
return [
tuple([int(x) for x in line.strip().split(',')])
for line in file
]
def solve(file, N=70, T=1024):
falling = parse(file)
start = (0,0,0) # x,y,t
map = [[0]*N for _ in range(N)]
inf = float('inf')
map = defaultdict(lambda: inf)
for t,p in enumerate(falling):
map[p] = t
def neighbors(n):
x,y,t = n
#if T < map[x,y]:
# can't move out of a blocked space
# return []
def push(x,y,t):
if 0 <= x < N and 0 <= y < N:
if T <= map[x,y]:
out.append((1,(x,y,t)))
out = []
push(x+1,y,t+1)
push(x,y+1,t+1)
push(x-1,y,t+1)
push(x,y-1,t+1)
return out
end = N-1, N-1
def isgoal(n):
x,y,_ = n
return (x,y) == end
sol = astar.search(start, isgoal, neighbors)
print(sol)
print(len(sol[-1])-1)
solve(open("sample1.in"), N=7, T=12)
solve(open("input"), N=71, T=1024)