adventofcode2022/day14/sol.py

source = (500,0)

data = []
for line in open("input"):
    path = []
    for point in line.replace("->", " ").split():
        x, y = map(int, point.split(","))
        path.append((x,y))
    data.append(path)


grid = {}

X0 = 500
X1 = 500 + 1
Y0 = 0
Y1 = 1

def put(x,y,c):
    global X0, X1, Y0, Y1
    if x < X0:  X0 = x
    if x >= X1: X1 = x + 1
    if y < Y0:  Y0 = y
    if y >= Y1: Y1 = y + 1
    grid[(x,y)] = c

def get(x,y):
    return grid.get((x,y), '.')

def minmax(a,b):
    if a < b:
        return a, b
    return b, a

def draw(path):
    for (x0,y0), (x1,y1) in zip(path, path[1:]):
        #print((x0,y0), (x1,y1))
        x0, x1 = minmax(x0, x1)
        y0, y1 = minmax(y0, y1)
        for y in range(y0, y1+1):
            put(x0,y, '#')
        for x in range(x0, x1+1):
            put(x,y0, '#')

for path in data:
    #print(path)
    draw(path)


def show():
    for y in range(Y0, Y1):
        print("".join(get(x,y) for x in range(X0, X1)))

show()

def drip(p, floor=None, lastpath=[]):
    x,y=p
    if p in lastpath:
        x,y = lastpath.pop()
    else:
        lastpath[:] = []
    blocked = False
    while not blocked:
        lastpath.append((x,y))
        if y+1 == floor:
            break
        if y >= Y1:
            return 'bye' # falls forever
        # try straight down, then left, then right
        for x1 in x, x-1, x+1:
            if get(x1,y+1) == '.':
                x,y = x1,y+1
                break # continue
        else:
            blocked = True
    # blocked!
    lastpath.pop()
    put(x,y,'o')
    #print(x,y)
    return 'done'

n = 0
while True:
    if drip(source) == 'bye':
        break
    n+= 1
print(n)

floor = Y1 + 1
Y1 = floor+1
show()

# keep going

while source not in grid:
    if drip(source, floor=floor) == 'bye':
        print("whoops") # shouldn't happen
        break
    n += 1

# 28594

#show()
print(n)