kamov/advent-of-code
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

2022 day 17

Browse source
This commit is contained in:
Maciej Jur 2022-12-18 13:03:27 +01:00
parent cfd15dcfeb
commit cbcb798f9f
1 changed files with 23 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

44
2022/rust/src/solutions/day17.rs
View file

@ -1,3 +1,4 @@
#![allow(dead_code)]
use std::collections::HashMap; use std::collections::HashMap;
use std::fmt::{Display, Formatter}; use std::fmt::{Display, Formatter};
use crate::utils; use crate::utils;
@ -143,36 +144,37 @@ fn solve1(data: &[Wind]) -> usize {
} }
fn solve2(data: &[Wind]) -> i64 { fn solve2(data: &[Wind]) -> i64 {
const BIG: i64 = 1_000_000_000_000;
let mut rocks = (0..ROCKS.len()).into_iter().cycle(); let mut rocks = (0..ROCKS.len()).into_iter().cycle();
let mut cave = Cave::new(data); let mut cave = Cave::new(data);
const BIG: i64 = 1_000_000_000_000; // Loop until cycle found
let mut cycle_metadata = vec![];
loop {
cave.insert(rocks.next().unwrap()).map(|meta| cycle_metadata.push(meta));
if cycle_metadata.len() > 1 { break };
}
for _ in 0..2022 { // We have to do this, because the first cycle can have corrupted height
if let Some((prev, curr, hist)) = cave.insert(rocks.next().unwrap()) { let cycle_h = cycle_metadata.pop().map(|(prev, curr, _)| curr.1 - prev.1).unwrap();
let (s, e) = (prev.0 - 1, curr.0 - 1);
let start = &hist[0..s];
let cycle = &hist[s..e];
let cycle_h = curr.1 - prev.1;
let from_start = hist[s-1].1 as i64; let (prev, curr, hist) = cycle_metadata.pop().unwrap();
let rocks_left = BIG - start.len() as i64; let (s, e) = (prev.0 - 1, curr.0 - 1);
let start = &hist[0..s];
let cycle = &hist[s..e];
let from_cycle = (rocks_left / cycle.len() as i64) * cycle_h as i64; let from_start = hist[s-1].1 as i64;
let rocks_left = rocks_left % cycle.len() as i64; let rocks_left = BIG - start.len() as i64;
// let from_above = match rocks_left > 0 { let from_cycle = (rocks_left / cycle.len() as i64) * cycle_h as i64;
// true => (cycle[rocks_left as usize - 1].1 - cycle[0].1) as i64, let rocks_left = rocks_left % cycle.len() as i64;
// false => 0,
// };
let ok = from_start + from_cycle; // + from_above; let from_above = match rocks_left > 0 {
assert!(ok < 1527906974720); true => (cycle[rocks_left as usize - 1].1 - cycle[0].1) as i64,
false => 0,
return ok;
};
}; };
-1
return from_start + from_cycle + from_above;
} }
fn parse_data<T: AsRef<str>>(data: &[T]) -> Vec<Wind> { fn parse_data<T: AsRef<str>>(data: &[T]) -> Vec<Wind> {