optimize d7p2

This commit is contained in:
nora 2024-12-07 14:50:59 +01:00
parent b1e24f6e1e
commit 3e9ff4ded0

View file

@ -14,6 +14,8 @@ helper::define_variants! {
part2 {
basic => crate::part2,sample_count=500;
no_string_fmt => crate::part2_no_string_fmt,sample_count=1000;
order => crate::part2_order,sample_count=1000;
parsing => crate::part2_parsing,sample_count=5000;
}
}
@ -127,6 +129,81 @@ fn part2_no_string_fmt(input: &str) -> u64 {
total
}
fn part2_order(input: &str) -> u64 {
let mut total = 0;
for line in input.lines() {
let (result, values) = line.split_once(": ").unwrap();
let result = parse_unwrap(result);
let values = values
.split(" ")
.map(|val| (val, parse_unwrap(val)))
.collect::<Vec<_>>();
fn does_work(values: &[(&str, u64)], result: u64) -> bool {
if values.len() == 1 {
return values[0].1 == result;
}
let (l_str, l) = *values.last().unwrap();
let next = &values[..(values.len() - 1)];
let thousand = 10_u64.pow(l_str.len() as u32);
let concat_works = result % thousand == l;
let mul_works = result % l == 0;
let sub_works = l <= result;
// Concat is the least common, so doing it first helps remove the most possibilities.
false
|| (concat_works && does_work(next, result / thousand))
|| (mul_works && does_work(next, result / l))
|| (sub_works && does_work(next, result - l))
}
if does_work(&values, result) {
total += result;
}
}
total
}
fn part2_parsing(input: &str) -> u64 {
let mut total = 0;
let mut values = Vec::new();
for line in input.lines() {
values.clear();
let (result, values_str) = line.split_once(": ").unwrap();
let result = parse_unwrap(result);
values.extend(values_str.split(' ').map(|val| (val, parse_unwrap(val))));
fn does_work(values: &[(&str, u64)], result: u64) -> bool {
if values.len() == 1 {
return values[0].1 == result;
}
let (l_str, l) = *values.last().unwrap();
let next = &values[..(values.len() - 1)];
let thousand = 10_u64.pow(l_str.len() as u32);
let concat_works = result % thousand == l;
let mul_works = result % l == 0;
let sub_works = l <= result;
// Concat is the least common, so doing it first helps remove the most possibilities.
false
|| (concat_works && does_work(next, result / thousand))
|| (mul_works && does_work(next, result / l))
|| (sub_works && does_work(next, result - l))
}
if does_work(&values, result) {
total += result;
}
}
total
}
helper::tests! {
day07 Day07;
part1 {
@ -135,7 +212,7 @@ helper::tests! {
}
part2 {
small => 11387;
default => 0;
default => 146111650210682;
}
}
helper::benchmarks! {}