adventofcode2022/day24/sol.py

data = []
for line in open("input"):
    data.append(line.strip())

import sys, os; sys.path.append(os.path.join(os.path.dirname(__file__), "../lib"))
import astar


#print(*data, sep="\n")

blizzards = {'>': {}, '<': {}, '^': {}, 'v': {}}
for y in range(len(data)):
    for x in range(len(data[y])):
        c = data[y][x]
        if c in blizzards:
            blizzards[c][x,y] = 1

def show(t):
    H = len(data)-2
    for y in range(len(data)):
        s = []
        W = len(data[y])-2
        for x in range(len(data[y])):
            c = data[y][x]
            if c == '#':
                s.append(c)
            else:
                bliz = []
                u = 1 + ((x - t)-1)%W
                if (u,y) in blizzards['>']:
                    bliz.append('>')

                u = 1 + ((x + t)-1)%W
                if (u,y) in blizzards['<']:
                    bliz.append('<')

                v = 1 + ((y - t)-1)%H
                if (x,v) in blizzards['v']:
                    bliz.append('v')

                v = 1 + ((y + t)-1)%H
                if (x,v) in blizzards['^']:
                    bliz.append('^')

                if len(bliz) == 0:
                    s.append('.')
                elif len(bliz) == 1:
                    s.append(bliz[0])
                elif len(bliz) < 10:
                    s.append(str(len(bliz)))
                else:
                    s.append('*')
            
        print(''.join(s))

def blocked(x,y,t):
    if not 0 <= y < len(data):
        return True
    if not 0 <= x < len(data[y]):
        return True
    if data[y][x] == '#':
        return True

    H = len(data)-2
    W = len(data[y])-2

    u = 1 + ((x - t)-1)%W
    if (u,y) in blizzards['>']:
        return True

    u = 1 + ((x + t)-1)%W
    if (u,y) in blizzards['<']:
        return True

    v = 1 + ((y - t)-1)%H
    if (x,v) in blizzards['v']:
        return True

    v = 1 + ((y + t)-1)%H
    if (x,v) in blizzards['^']:
        return True

    return False

start = (data[0].index('.'), 0)
goal = (data[-1].index('.'), len(data)-1)
leg_distance = abs(start[0] - goal[0]) + abs(start[1] - goal[1])

def is_goal(node):
    x, y, t, legs = node
    return (x,y) == goal and legs == 0

def heuristic(node):
    x, y, t, legs = node
    if legs == 0:
        return 0
    if legs % 2 == 1:
        g = goal
    else:
        g = start
    return (legs-1)*leg_distance + abs(g[0] - x) + abs(g[1] - y)

def neighbors(node):
    x, y, t, legs = node
    n = []
    if legs % 2 == 1:
        g = goal
    else:
        g = start
    def check(dx,dy):
        if not blocked(x+dx,y+dy,t+1):
            l = legs - ((x+dx,y+dy) == g)
            n.append((1, (x+dx, y+dy, t+1, l)))
    check(+1,0)
    check(0,+1)
    check(-1,0)
    check(0,-1)
    check(0,0)
    return n

show(0)
show(1)
#show((len(data)-2)*(len(data[0])-2))

start_node = start + (0, 1)
print(astar.search(start_node, is_goal, neighbors, heuristic))

start_node = start + (0, 3)
print(astar.search(start_node, is_goal, neighbors, heuristic))