mirror of
https://github.com/peter-tanner/advent-of-code-2020.git
synced 2024-11-30 10:50:17 +08:00
36 lines
1.1 KiB
Python
36 lines
1.1 KiB
Python
import math
|
||
|
||
d = [ x.split(',') for x in open('input').read().splitlines() ]
|
||
|
||
def a(d): #To be honest, I could've done this way quicker manually and got on the leaderboard. Formula is x - ID mod x for the waiting time
|
||
x = int(d[0][0])
|
||
ids = [ int(x) for x in d[1] if x != 'x' ]
|
||
delta = { id:(id - (x % id)) for id in ids if ( x := int(d[0][0]) )}
|
||
minId = min(delta, key=delta.get)
|
||
return (delta[minId]*minId)
|
||
|
||
print(a(d))
|
||
|
||
def b(d):
|
||
d = [ [-y,int(d[y])] for y in {i:d[i] for i in range(len(d))} if d[y] != 'x']
|
||
[ print(x) for x in d ] # generate numbers
|
||
|
||
|
||
# I'm a math noob, so I just saw what everyone else is talking about and found this chinese remainder theorem.
|
||
# Why does this work? I DONT KNOW.
|
||
# I'll probably learn this when I get some formal CS education.
|
||
# Used a solver for that.
|
||
|
||
# x = 760171380521445
|
||
# x ≡ 0 mod 17 => x = n*17+0
|
||
# x ≡ −7 mod 41 => x = n*41-7 ??? # -7 because of
|
||
# x ≡ −17 mod 643
|
||
# x ≡ −25 mod 23
|
||
# x ≡ −30 mod 13
|
||
# x ≡ −46 mod 29
|
||
# x ≡ −48 mod 433
|
||
# x ≡ −54 mod 37
|
||
# x ≡ −67 mod 19
|
||
|
||
b(d[1])
|