ktims/aoc2023
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

day14: simple Vec lookup is faster than HashMap since the cycle is short

Browse Source
This commit is contained in:
Keenan Tims 2023-12-14 15:41:34 -08:00
parent ca3254e1e1
commit 4f1f838d62
No known key found for this signature in database
GPG Key ID: B8FDD4AD6B193F06
1 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
14/src/main.rs
View File

@ -1,5 +1,5 @@
use ndarray::*; use ndarray::*;
use std::collections::HashMap;
use std::fmt::Display; use std::fmt::Display;
use std::fs::File; use std::fs::File;
@ -162,14 +162,16 @@ impl<'a> Platform {
// find the first loop, return the iteration count when we first saw it and when we saw it again // find the first loop, return the iteration count when we first saw it and when we saw it again
fn find_loop(&mut self) -> (usize, usize) { fn find_loop(&mut self) -> (usize, usize) {
let mut first_seen = HashMap::new(); let mut first_seen = Vec::new();
first_seen.insert(self.matrix.clone(), 0); first_seen.push((self.matrix.clone(), 0));
let mut i = 0; let mut i = 0;
loop { loop {
self.roll_cycle(); self.roll_cycle();
i += 1; i += 1;
if let Some(first_idx) = first_seen.insert(self.matrix.clone(), i) { if let Some((_, first_idx)) = first_seen.iter().find(|(val, _)| *val == self.matrix) {
return (first_idx, i); return (*first_idx, i);
} else {
first_seen.push((self.matrix.clone(), i));
} }
} }
} }