22
https://adventofcode.com/2024/day/22
Prob1
python
import sys
N = (1 << 24) - 1
sum = 0
for line in sys.stdin:
x = int(line)
for i in range(2000):
x = ((x << 6) ^ x) & N
x = ((x >> 5) ^ x) & N
x = ((x << 11) ^ x) & N
sum += x
print(sum)Prob2
python
import sys
from typing import Dict, Tuple, List
N = (1 << 24) - 1
def next_rand(x):
x = ((x << 6) ^ x) & N
x = ((x >> 5) ^ x) & N
x = ((x << 11) ^ x) & N
return x
def seq_map(seed: int) -> Dict[Tuple[int, int, int, int], int]:
prices = []
x = seed
for i in range(2001):
prices.append(x % 10)
x = next_rand(x)
diff_prices = []
for i in range(2000):
diff_prices.append(prices[i+1] - prices[i])
ret = {}
for i in range(2000 - 4 + 1):
key = (diff_prices[i],
diff_prices[i+1],
diff_prices[i+2],
diff_prices[i+3])
ret.setdefault(key, prices[i+4])
return ret
sum = 0
seeds = []
for line in sys.stdin:
x = int(line)
seeds.append(x)
seed_seq_map: List[Dict[Tuple[int, int, int, int], int]] = []
keys = set() # size <= 21**4
for s in seeds:
seed_seq_map.append(seq_map(s))
keys |= set(seed_seq_map[-1].keys())
print(len(keys))
ans = -123456789
for key in keys:
price_sum = 0
for smap in seed_seq_map:
price_sum += smap.get(key, 0)
if price_sum >= ans:
ans = price_sum
print(key, price_sum)
print(ans)