@arnauddelobelle.bsky.social
![# AOC 2025 Day 9 - expect input on stdin
red = [eval(l.strip()) for l in open(0)]
def I(a, b): return range(min(a, b), max(a, b) + 1)
def A(a, b): return len(I(a[0], b[0]))*len(I(a[1], b[1]))
xs = sorted({x for x,_ in red} | {-1, 1000000})
ys = sorted({y for _,y in red} | {-1, 1000000})
kred = [(xs.index(x), ys.index(y)) for x, y in red]
kgrid = [['.']*len(xs) for _ in ys] # Kompress the grid!
lx, ly = kred[-1] # Draw the lines
for x, y in kred:
for x1 in I(lx, x):
for y1 in I(ly, y): kgrid[y1][x1] = '#'
lx, ly = x, y
stack = [(0, 0)] # Remove the outside
while stack:
x, y = stack.pop()
if 0 <= x < len(xs) and 0 <= y < len(ys) and kgrid[y][x] == '.':
kgrid[y][x] = ' '
stack.extend([(x+1,y), (x-1, y), (x, y+1), (x, y-1)])
print(max(A(a, b) for i, a in enumerate(red) for b in red[:i])) # Part 1
print(max(A((xs[x1], ys[y1]), (xs[x2], ys[y2]))
for i, (x1,y1) in enumerate(kred) for (x2,y2) in kred[:i]
if all(kgrid[y][x] != ' ' for x in I(x1, x2) for y in I(y1, y2))
)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreieyrspbazkx4t4x2sijf7364cwlf47725dqxm7wi4lhsxdss7b3cy@jpeg)
![# AOC 2025 Day 8 - expect input on stdin
boxes = sorted(eval(l.strip()) for l in open(0))
def d2(a, b): return (b[0]-a[0])**2 + (b[1]-a[1])**2 + (b[2]-a[2])**2
close = sorted((d2(a, b), a, b) for i, a in enumerate(boxes) for b in boxes[:i])
circuits = []
for n, (_, a, b) in enumerate(close):
if n == 1000:
x, y, z = sorted((len(c) for c in circuits), reverse=True)[:3]
print(x*y*z) # Part 1
cont = [c for c in circuits if a in c or b in c]
if not cont:
circuits.append({a,b})
elif len(cont) == 2:
c1, c2 = cont
c1.update(c2)
circuits.remove(c2)
else:
c, = cont
if not(a in c and b in c):
c.add(a)
c.add(b)
if len(circuits[0]) == len(boxes):
print(a[0]*b[0]) # Part 2
break](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreiaurfyrxsgfp2gmqtjkvesapxbzwa5ig7ng6is5yllehtuhvsfo2m@jpeg)
December 9, 2025 at 9:09 PM
![# AOC 2025 Day 7 - expect input on stdin
T, *Sv = [[c != '.' for c in l.strip()] for l in open(0)]
splits, n = 0, len(T)
for S in Sv:
splits += sum(1 for t, z in zip(T, S) if t > 0 and z)
T = [T[i]*(1-S[i])
+ (i>0 and T[i-1]*S[i-1])
+ (i+1<n and T[i+1]*S[i+1])
for i in range(n)]
print(splits) # Part 1
print(sum(T)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreibobc2jjm6t6un4ackjlv6f4pirl7nb664ef4pyglq2jh6fqojkbu@jpeg)
December 9, 2025 at 9:07 PM
![# Day 6 - expect input on stdin
import operator as op
lines = [l.strip('\n') for l in open(0)]
# Part 1
print(sum(eval(c.join(ns))
for c, *ns in zip(*[l.split() for l in lines[::-1]])))
nums = [''.join(z) for z in zip(*lines[:-1])]
S, s, f = 0, 0, op.add
for i, c in enumerate(lines[-1]):
if c != ' ':
S, s = S+s, int(nums[i])
f = op.add if c == '+' else op.mul
elif nums[i].strip() != '':
s = f(s, int(nums[i]))
print(S+s) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreieaxt2bndm7cva3qmx3fzoi7jwsd7lj6ysqdefqgzbslabspkn4ay@jpeg)
December 9, 2025 at 9:05 PM
![# Day 5 - expect input on stdin
S1, S2 = open(0).read().split('\n\n')
R = [(int(x), int(y)) for x, y in (l.split('-') for l in S1.split())]
I = [int(x) for x in S2.split()]
print(sum(1 for i in I if any(x <= i <= y for x, y in R))) # Part 1
count, level = 0, 0.5
for x, d in sorted(i for x, y in R for i in ((x-1, -1), (y, 1))):
if (level + d) * level < 0:
count += x*d
level += d
print(count) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreid6nicvx553ddimyvb5eddelbivy32tfs5scd4mpnb2lskiq4zhc4@jpeg)
December 9, 2025 at 9:02 PM
December 4, 2025 at 8:38 PM
![# Day 3 - expect input on stdin
banks = [l.strip() for l in open(file=0)]
def max_joltage(bank, n):
i, js = 0, ''
for j in range(len(bank)-n, len(bank)):
i, ds = max(enumerate(bank[i:j+1], i+1), key=lambda x: x[1])
js += ds
return int(js)
print(sum(max_joltage(b, 2) for b in banks)) # Part 1
print(sum(max_joltage(b, 12) for b in banks)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreifivasyqmqqo4mljgyh42bfl5hzawrc7v7eqt2hdrjjuk643q47py@jpeg)
December 4, 2025 at 8:34 PM
![# Day 2 - expect input on stdin
ranges = [r.split('-') for r in open(0).read().split(",")]
def next_silly(n, splitmax, incl):
l, silly = len(n), ''
for d in range(2, (splitmax or l) + 1):
if l % d: continue
i = l // d
s = n[:i]*d
if s > n or incl and s == n:
silly = min(silly, s) or s
p = str(int(n[:i]) + 1)
if len(p) == i:
s = p*d
silly = min(silly, s) or s
return silly or next_silly('1'+'0'*l, splitmax, incl)
def silly_iter(n1, n2, splitmax=None):
silly = next_silly(n1, splitmax, incl=True)
while int(silly) <= int(n2):
yield int(silly)
silly = next_silly(silly, splitmax, incl=False)
def silly_sum(splitmax=None):
return sum(s for n1, n2 in ranges for s in silly_iter(n1, n2, splitmax))
print(silly_sum(2)) # Part 1
print(silly_sum()) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreiaqsu7dzgflbhcbdhlittgps3n5l4kl5oych2qezg7lwtsihggshm@jpeg)
December 4, 2025 at 8:33 PM
![# Day 1 - expect input on stdin
import sys
rots = [(2*(l[0] == 'R') - 1)*int(l[1:]) for l in sys.stdin]
n, p1, p2 = 50, 0, 0
for r in rots:
p2 += abs(n + r) // 100 + (n > 0 and n + r <= 0)
n = (n + r) % 100
p1 += not n
print(p1) # Part 1
print(p2) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreidfosygvvfrfhqx7s4gjftrkiqik3gzqra7q5pvmho7vsra6hygne@jpeg)
December 1, 2025 at 10:24 PM
I just completed all 25 days of Advent of Code 2024! #AdventOfCode adventofcode.com
Advent of Code 2024
adventofcode.com
December 25, 2024 at 9:26 AM
I just completed all 25 days of Advent of Code 2024! #AdventOfCode adventofcode.com
![# AOC 2024 Day 23 - expect input on stdin
from collections import defaultdict
pairs = [tuple(l.strip().split('-')) for l in open(0)]
conns = defaultdict(set)
for a, b in pairs: conns[a].add(b); conns[b].add(a)
triples = {
(*sorted((a, b, c)),)
for a, b in pairs for c, R in conns.items()
if {a, b} <= R and c.startswith('t')
}
complete = [{c} for c in conns]
for c, R in conns.items():
for K in complete:
if K <= R: K.add(c)
print(len(triples)) # Part 1
print(','.join(sorted(max(complete, key=len)))) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreifor5inbm3a5gbl4gxzqyf4pbqkpy6yuszj7mh7mq5zjvgglhnyzm@jpeg)
December 23, 2024 at 5:40 PM
![# AOC 2024 Day 22 - expect input on stdin
from collections import Counter
from itertools import islice, pairwise
S = [int(l) for l in open(0)]
def secrets(s, N=(1 << 24) - 1):
while True:
yield s
s = (s ^ (s << 6) ) & N
s = (s ^ (s >> 5) ) & N
s = (s ^ (s << 11)) & N
print(sum(next(islice(secrets(s), 2000, None)) for s in S)) # Part 1
totals = Counter()
for s in S:
seen, dp = set(), []
for s1, s2 in pairwise(islice(secrets(s), 2001)):
dp.append(s2%10 - s1%10)
seq = tuple(dp[-4:])
if len(seq) >= 4 and seq not in seen:
seen.add(seq)
totals[seq] += s2%10
print(*max(totals.most_common(1))) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreiao6rpn76t3k2sj6adhvaqzabh2fy45bnkqrwobvfu4l3jzlahlbq@jpeg)
December 22, 2024 at 1:58 PM
![# AOC 2024 Day 21 - expect input on stdin
from functools import cache
from itertools import pairwise
codes = [*open(0).read().splitlines()]
D, R = (' 0A','123','456','789'), ('<v>',' ^A')
def pos(k, K):
return next((r.index(k), y) for y, r in enumerate(K) if k in r)
def moves(k0, k1, K):
(x0, y0), (x1, y1) = pos(k0, K), pos(k1, K)
dx, dy = x1 - x0, y1 - y0
mx, my = '<>'[dx>0]*abs(dx), 'v^'[dy>0]*abs(dy)
if K[y0][x1] != ' ': yield mx + my + 'A'
if K[y1][x0] != ' ': yield my + mx + 'A'
@cache
def move_cplx(k0, k1, n, K):
return n < 0 or min(cplx(seq, n-1, R) for seq in moves(k0, k1, K))
def cplx(seq, n, K=D):
return sum(move_cplx(k0, k1, n, K) for k0, k1 in pairwise('A'+seq))
print(sum(int(code[:3])*cplx(code, 2) for code in codes)) # Part 1
print(sum(int(code[:3])*cplx(code, 25) for code in codes)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreiebfdpnvis4n6eicjhwfwdy7244x54wsjl2jt6az5stndeqrwsou4@jpeg)
December 21, 2024 at 10:49 PM
![# AOC 2024 Day 20 - expect input on stdin
M = [*open(0).read().splitlines()]
x, y = next((r.index("S"), y) for y, r in enumerate(M) if "S" in r)
pE = next((r.index("E"), y) for y, r in enumerate(M) if "E" in r)
time = {(x, y): 0}
while (x, y) != pE:
for (x, y) in [(x+1,y), (x,y+1), (x-1,y), (x,y-1)]:
if M[y][x] != '#' and (x, y) not in time: break
time[x,y] = len(time)
def cheats(sz):
for p1 in time:
for dx in range(sz + 1):
for dy in range(dx - sz if dx else 1, sz + 1 - dx):
if (p2 := (p1[0]+dx, p1[1]+dy)) in time:
yield abs(time[p1] - time[p2]) - dx - abs(dy)
print(sum(1 for c in cheats(2) if c >= 100)) # Part 1
print(sum(1 for c in cheats(20) if c >= 100)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreihbgbveetwiooaaseamjrwyi2dquqm4u3c6b2smvj7falynsdjp4u@jpeg)
December 20, 2024 at 9:54 PM
![# AOC 2024 Day 19 - expect input on stdin
from functools import cache
ds, ps = open(0).read().split('\n\n')
D , P = ds.split(", "), ps.split()
@cache
def arrs(p):
return not p or sum(arrs(p[len(d):]) for d in D if p.startswith(d))
print(sum(arrs(p) > 0 for p in P)) # Part 1
print(sum(arrs(p) for p in P)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreigwrtyezt2yzx2s5jhryfcdqjhym6emc5cki3ubai6lq3w4agudtq@jpeg)
December 19, 2024 at 7:34 PM
![# AOC 2024 Day 18 - expect input on stdin
P = [tuple(map(int, l.split(','))) for l in open(0)]
M = {(x, y) for x in range(71) for y in range(71)} - set(P[:1024]) # type: ignore
def solve(M):
n, seen, edge = 0, set(), [(0, 0)]
while edge and (70,70) not in seen:
edge = set(p for (x,y) in edge
for p in [(x+1,y), (x,y+1), (x-1,y), (x,y-1)]
if p in M and p not in seen)
n += 1; seen |= edge
return edge and n
print(solve(M)) # Part 1
p = next(p for p in P[1024:] if M.remove(p) or not solve(M))
print("%d,%d" % p) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreidckgm6hfxwj7psx57l7wz55ds5ubnfbeidilydyy5plnllavrbrm@jpeg)
December 18, 2024 at 7:54 PM
![# AOC 202 Day 17 - expect input on stdin
import re
rA, rB, rC, *prg = map(int, re.findall(r'\d+', open(0).read()))
A, B, C, PC = 0, 1, 2, 3
def v(r, x): return x if x < 4 else r[x - 4]
def adv(r, x): r[A] = r[A] >> v(r, x)
def bxl(r, x): r[B] = x ^ r[B]
def bst(r, x): r[B] = v(r, x) % 8
def jnz(r, x): r[PC] = x - 2 if r[A] else r[PC]
def bxc(r, x): r[B] = r[B] ^ r[C]
def out(r, x): return (v(r, x) % 8)
def bdv(r, x): r[B] = r[A] >> v(r, x)
def cdv(r, x): r[C] = r[A] >> v(r, x)
I = [adv, bxl, bst, jnz, bxc, out, bdv, cdv]
def run(r):
while r[PC] < len(prg):
output = I[prg[r[PC]]](r, prg[r[PC]+1])
if output is not None: yield output
r[PC] += 2
def check(rA, n):
return sum(a == b for a, b in zip(prg[:n], run([rA, rB, rC, 0]))) == n
def search():
d = 1 << 7; S = range(d)
for n in range(1, len(prg) + 1):
S = [rA for s in S for rA in range(s, s + (d << 3), d) if check(rA, n)]
d <<= 3
return S
print(','.join(map(str, run([rA, rB, rC, 0])))) # Part 1
print(min(search())) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreigkgk5ypfxmg735lifffjwrixzy4flblkipnjnqys2yeeqho7l4yi@jpeg)
![# AOC 2024 Day 16 - expect input on stdin
M = [*open(0).read().splitlines()]
pS = next((r.index("S"), y) for y, r in enumerate(M) if "S" in r)
pE = next((r.index("E"), y) for y, r in enumerate(M) if "E" in r)
dx, dy = zip((1, 0), (0, 1), (-1, 0), (0, -1))
def rot(r): return lambda x, y, d: (x, y , (d + r)%4)
def adv(x, y, d): return (x+dx[d], y+dy[d], d)
def fill(scores):
edge = [*scores.items()]
def advance():
for pv, score in edge:
for cost, f in [(1000, rot(1)), (1000, rot(3)), (1, adv)]:
pv1, score1 = f(*pv), score + cost
x, y = pv1[:2]
if M[y][x] != '#' and scores.get(pv1, 1e9) > score1:
scores[pv1] = score1
yield pv1, score1
while edge: edge = [*advance()]
fill(S := {(*pS, 0): 0})
lowscore = min(S[pv] for pv in S if pv[:2] == pE)
print(lowscore) # Part 1
fill(RS := {(rot(2)(*pv)): -lowscore for pv in S if S[pv] == lowscore})
best_pos = {pv[:2] for pv, s in S.items() if RS[rot(2)(*pv)] == -s}
print(len(best_pos)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreid4iuykg2qsukotzj5yl6kiij6ih5e7323neu2aitd4o3h7coru24@jpeg)
December 16, 2024 at 9:05 PM
![# AOC 2024 Day 15 - expect input on stdint
E = enumerate
ws, M = open(0).read().split('\n\n')
W1 = [[*l] for l in ws.splitlines()]
T = {'.': '..', '@': '@.', '#': '##', 'O': '[]'}
W2 = [[t for c in r for t in T[c]] for r in W1]
mvec = {'^': (0,-1), '>': (1,0), 'v': (0,1), '<': (-1,0)}
def push(W, x, y, dx, dy, do=True):
can = (c := W[y][x]) != '#'
if c in 'O@' or dx and c in '[]':
can = push(W, x+dx, y+dy, dx, dy, do)
if do: W[y][x], W[y+dy][x+dx] = '.', c
elif c in '[]':
x0 = x - '[]'.index(c)
can = push(W, x0, y+dy, 0, dy, do) and push(W, x0+1, y+dy, 0, dy, do)
if do: W[y][x0:x0+2], W[y+dy][x0:x0+2] = '..', '[]'
return can
def solve(W):
x, y = next((x,y) for y,r in E(W) for x,c in E(r) if c == '@')
for dx, dy in [mvec[c] for c in M if c in mvec]:
if push(W, x, y, dx, dy, do=False):
push(W, x, y, dx, dy); x += dx; y += dy
return sum(x + 100*y for y,r in E(W) for x,c in E(r) if c in 'O[')
print(solve(W1)) # Part 1
print(solve(W2)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreier23r2es5fublzhmkavt3ex3w7jxrwnjp3ls4ewbjfe2szvlvtdy@jpeg)
December 15, 2024 at 7:08 PM
![# AOC 2024 Day 14 - expect input on stdin
import re, itertools
w, h = 101, 103
R = [[int(d) for d in re.findall(r'-?\d+', txt)] for txt in open(0)]
def move(n, x, y, dx, dy): return (x + n*dx) % w, (y + n*dy) % h
def safety_factor(R, n, xm=w//2, ym=h//2, Q=[0]*4):
for x, y in (move(n, *r) for r in R):
if x != xm and y != ym: Q[2*(x>xm)+(y>ym)] += 1
return Q[0]*Q[1]*Q[2]*Q[3]
def display(P):
for y in range(h):
print(''.join('XX' if (x,y) in P else '. ' for x in range(w)))
def find_tree(R):
for n in itertools.count(1):
P = {move(n, *r) for r in R}
vf, hf = [0]*h, [0]*w
for x, y in P: hf[x] += 1; vf[y] += 1
if max(*hf) >= 30 and max(*vf) >= 20: display(P); return n
print(safety_factor(R, 100)) # Part 1
print(find_tree(R)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreiffalqygg3je6olwtoiehfpsmufxsrh5om2mctqnjfvesnt7oexlu@jpeg)
December 14, 2024 at 10:46 AM
![# AOC 2024 Day 13 - expect input on stdin
import re
def solve1(ax, ay, bx, by, px, py):
if max(px / (ax + bx), py / (ay + by)) > 100: return 0
return count(ax, ay, bx, by, px, py, 100)
def solve2(ax, ay, bx, by, px, py, M=10_000_000_000_000):
a0 = M*(by - bx)//(ax*by - bx*ay) - 1000
b0 = M*(ay - ax)//(bx*ay - ax*by) - 1000
qx, qy = px + M - a0*ax - b0*bx, py + M - a0*ay - b0*by
c = count(ax, ay, bx, by, qx, qy, M)
return c and c + 3*a0 + b0
def count(ax, ay, bx, by, px, py, a_max):
if ax > 3*bx: a, b = search(ax, ay, bx, by, px, py, a_max)
else: b, a = search(bx, by, ax, ay, px, py, a_max)
return 3*a + b
def search(ax, ay, bx, by, px, py, a_max):
a = min(px // ax, py // ay, a_max)
rx, ry = px - a*ax, py - a*ay
while a > -1:
if rx % bx == 0 and ry % by == 0:
b1, b2 = rx // bx, ry // by
if b1 == b2: return a, b1
rx, ry, a = rx+ax, ry+ay, a-1
return 0, 0
toks1, toks2 = zip(*((solve1(*data), solve2(*data))
for data in ([int(d) for d in re.findall(r'\d+', txt)]
for txt in open(0).read().split('\n\n'))))
print(sum(toks1)) # Part 1
print(sum(toks2)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreibgf7zc7ofohu2oxjyoz44unv62ldk2chnb2q6vn3pigsvdrwcov4@jpeg)
December 13, 2024 at 7:59 PM
![# AOC 2024 Day 12 - expect input on stdin
I, APS = {}, []
def update_aps(i, da, dp, ds):
a, p, s = APS[i]; APS[i] = a+da, p+dp, s+ds
for y, l in enumerate(open(0)):
for x, c in enumerate(l.strip()):
i_w, i_n = I.get((x-1, y, c)), I.get((x, y-1, c))
if i_w is None and i_n is None:
I[x, y, c] = len(APS)
APS.append((1, 4, 2))
elif i_w is None:
I[x, y, c] = i_n
update_aps(i_n, 1, 2, ((x-1, y-1, c) in I) + ((x+1, y-1, c) in I))
elif i_n is None:
I[x, y, c] = i_w
update_aps(i_w, 1, 2, (x-1, y-1, c) in I)
else:
if i_w != i_n:
update_aps(i_w, *APS[i_n])
APS[i_n] = 0, 0, 0
I.update((k, i_w) for k, i_k in I.items() if i_k == i_n)
I[x, y, c] = i_w
update_aps(i_w, 1, 0, -((x+1, y-1, c) not in I))
print(sum(a*p for a, p, _ in APS)) # Part 1
print(2*sum(a*s for a, _, s in APS)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreifu3oa6j66ul7czeizhajbxbgnsqyck2srfhtvyz3fs4p3tt6qohu@jpeg)
December 12, 2024 at 9:48 PM
![# AOC 2024 Day 11 - expect input on stdin
from functools import cache
V = [int(s) for s in open(0).read().split()]
@cache
def count(v, n):
if n == 0: return 1
if v == 0: return count(1, n-1)
s = str(v); k = len(s)
if k % 2: return count(v*2024, n-1)
return count(int(s[:k//2]), n-1) + count(int(s[k//2:]), n-1)
print(sum(count(v, 25) for v in V)) # Part 1
print(sum(count(v, 75) for v in V)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreihsxx2sni4xscy4hhv3t3naann63xmaior3xm3efd2lkkhedwvjbq@jpeg)
December 11, 2024 at 10:27 PM
![# AOC 2024 Day 10 - expect input on stdin
from functools import cache
M = {(x, y): int(h) for y, l in enumerate(open(0))
for x, h in enumerate(l.strip())}
dirs = (0,1), (0,-1), (1,0), (-1,0)
@cache
def rec(p, n=0):
if M.get(p) != n: return 0, set()
if n == 9: return 1, {p}
ratings, tailsets = zip(*(rec((p[0]+u, p[1]+v), n+1) for u,v in dirs))
return sum(ratings), set.union(*tailsets)
ratings, tailsets = zip(*map(rec, M))
print(sum(len(tails) for tails in tailsets)) # Part 1
print(sum(ratings)) # Part 2](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreibmj4zvigz23vsejxk7765trlf43f2wioolis2675bdjuwn2rdn5a@jpeg)
December 10, 2024 at 10:11 PM
![# AOC 2024 Day 9 - expect input on stdin
S = open(0).read()
M = [-1 if i%2 else i//2 for i, a in enumerate(S) for _ in range(int(a))]
while -1 in M:
j = M.index(-1)
while (m := M.pop()) == -1: pass
M[j] = m
print(sum(i*j for i, j in enumerate(M))) # Part 1
M2 = [(-1 if i%2 else i//2, int(a)) for i, a in enumerate(S)]
for j in range(len(M2)-1, -1, -1):
i, n = M2[j]
if i != -1:
k, m = next(((k, m) for k, (a, m) in enumerate(M2[:j])
if a == -1 and m >= n), (-1, 0))
if k >= 0:
M2[j] = -1, n
M2[k:k+1] = [(i, n), (-1, m - n)]
print(sum(i*j if j > 0 else 0 # Part 2
for i, j in enumerate(i for i, a in M2 for _ in range(a))))](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:lluzy7kvsuszpz3cle5vt64s/bafkreiajy7xxlseezthbhl7wzyzvr2yi5fqpsdob55g6uep4ow2ocnwxzi@jpeg)
December 9, 2024 at 10:02 PM