ollien
/
advent-of-code-2019
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Speed up day 16

master
Nick Krichevsky 2019-12-17 17:47:13 -05:00
parent 0a7f1eebea
commit e05d0c5578
1 changed files with 10 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
day16/py/main.py
View File

@ -1,6 +1,6 @@
import sys import sys
import math import math
from typing import Tuple from typing import Tuple, List
BASE_PATTERN = (0, 1, 0, -1) BASE_PATTERN = (0, 1, 0, -1)
@ -20,14 +20,17 @@ def stretch_pattern(i: int, length: int) -> Tuple[int, ...]:
return trimmed_pattern return trimmed_pattern
def generate_second_half(input_num: str): def generate_second_half(input_num: str) -> str:
res = ''
last_sum = 0 last_sum = 0
for char in reversed(input_num): # It is much much faster if, instead of concating a result as a string, we replace the results in a list in-place
last_sum = int(char) + int(last_sum) # We could probably make this faster if we mutated a list each time instead of making a new list, but this is
res = str(last_sum % 10) + res # good enough(tm)
input_list = [int(digit) for digit in input_num]
for i, digit in reversed(tuple(enumerate(input_list))):
last_sum = digit + last_sum
input_list[i] = str(last_sum % 10)
return res return ''.join(input_list)
def run_pattern_round(input_num: str, offset: int) -> str: def run_pattern_round(input_num: str, offset: int) -> str:
@ -62,7 +65,6 @@ def part1(input_num: str) -> str:
def part2(input_num: str) -> str: def part2(input_num: str) -> str:
# This is super super slow (about 7 mins on my PC.) Need to find a way to speed it up
offset = int(input_num[:7]) offset = int(input_num[:7])
return generate_all_pattern_rounds(input_num * 10000, offset)[:8] return generate_all_pattern_rounds(input_num * 10000, offset)[:8]