From 239398fe0b908da785a4100db9f1a44f99aed740 Mon Sep 17 00:00:00 2001 From: mhsn Date: Wed, 20 Aug 2025 14:51:44 +0100 Subject: 2024-09 rust p1 --- 2024/09/rust/src/main.rs | 51 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 2024/09/rust/src/main.rs (limited to '2024/09/rust/src') diff --git a/2024/09/rust/src/main.rs b/2024/09/rust/src/main.rs new file mode 100644 index 0000000..1fb892f --- /dev/null +++ b/2024/09/rust/src/main.rs @@ -0,0 +1,51 @@ +#![feature(iter_array_chunks)] + +use std::io; + +fn main() -> io::Result<()> { + let disk_map = io::stdin() + .lines() + .flatten() + .next() + .unwrap() + .chars() + .map(|c| c as u8 - b'0') + .collect(); + + let silver: usize = silver(&disk_map); + let gold: u64 = 0; + println!("silver: {silver}"); + println!("gold: {gold}"); + + return Ok(()); +} + +fn silver(input: &Vec) -> usize { + let mut blocks = input + .iter() + .chain([0, 0].iter()) // lol + .array_chunks() + .enumerate() + .map(|(n, [&f, &s])| [[Some(n)].repeat(f as usize), [None].repeat(s as usize)]) + .flatten() + .flatten() + .collect::>(); + + let mut l = 0; + let mut r = blocks.len() - 1; + loop { + while blocks[r].is_none() { + r -= 1; + } + while blocks[l].is_some() { + l += 1; + } + if l >= r { + break; + } + let [left, right] = blocks.get_disjoint_mut([l, r]).unwrap(); + left.replace(right.take().unwrap()); + } + + blocks.iter().enumerate().map(|(n, id)| n * id.unwrap_or_default()).sum() +} -- cgit v1.2.3