adventofcode2022/day12/alt.py

54 lines
1.2 KiB
Python

import string
import sys, os; sys.path.append(os.path.join(os.path.dirname(__file__), "../lib"))
import astar
elevation = {c:i for i, c in enumerate(string.ascii_lowercase)}
elevation['E'] = elevation['z']
elevation['S'] = elevation['a']
data = open("input").read().splitlines(False)
#print(*data, sep="\n")
extra = []
for y, row in enumerate(data):
for x, c in enumerate(row):
if c == 'S':
start = (x,y)
elif c == 'E':
goal = (x,y)
elif c == 'a':
# for part 2
extra.append((x,y))
def get(x, y):
return elevation[data[y][x]]
def solve(part):
def neighbors(src):
x,y = src
here = get(x,y)
n = []
def push(x,y):
if 0 <= y < len(data):
if 0 <= x < len(data[y]):
if get(x,y) <= here+1:
n.append((1, (x,y)))
push(x-1, y)
push(x+1,y)
push(x, y-1)
push(x, y+1)
return n
def heuristic(n):
return abs(goal[0] - n[0]) + abs(goal[1] - n[1])
s = [start]
if part == 2:
s += extra
print(part, "=", astar.search(s, goal, neighbors, heuristic))
solve(1)
solve(2)