Day 9 shenanigans

This commit is contained in:
Tyler Beckman 2023-12-08 22:49:11 -07:00
parent d33a6fb539
commit 6882c31777
Signed by: Ty
GPG key ID: 2813440C772555A4
2 changed files with 98 additions and 1 deletions

94
src/day9/mod.rs Normal file
View file

@ -0,0 +1,94 @@
use std::collections::HashMap;
use crate::utils::Day;
#[derive(Debug, Default)]
pub struct Day9 {
pub input: String,
}
impl Day for Day9 {
fn part1(&mut self) -> String {
let sequences = self.input.lines().map(|l| l.split_ascii_whitespace().map(|n| n.parse::<isize>().unwrap()).collect::<Vec<_>>());
let mut acc = 0i128;
for sequence in sequences {
let mut i = 1usize;
let len = sequence.len();
let mut sequence_map = HashMap::<usize, Vec::<isize>>::new();
sequence_map.insert(0, sequence.into_iter().rev().collect());
loop {
let mut new = Vec::<isize>::with_capacity(len-i);
let mut past: Option<isize> = None;
for num in sequence_map.get(&(i-1)).unwrap() {
if let Some(past_unwrapped) = past {
new.push(past_unwrapped - num);
}
past = Some(*num);
}
let done = new.iter().all(|n| n == &0);
if done { new.push(0); }
sequence_map.insert(i, new);
if done { break }
else { i += 1; }
}
for j in (0..=i).rev() {
let diff = *sequence_map.get(&j).unwrap().first().unwrap();
let Some(modify_arr) = sequence_map.get_mut(&(j-1)) else { break };
modify_arr.insert(0, *modify_arr.first().unwrap() + diff);
}
acc += sequence_map[&0][0] as i128;
}
acc.to_string()
}
fn part2(&mut self) -> String {
let sequences = self.input.lines().map(|l| l.split_ascii_whitespace().map(|n| n.parse::<isize>().unwrap()).collect::<Vec<_>>());
let mut acc = 0i128;
for sequence in sequences {
let mut i = 1usize;
let len = sequence.len();
let mut sequence_map = HashMap::<usize, Vec::<isize>>::new();
sequence_map.insert(0, sequence.into_iter().rev().collect());
loop {
let mut new = Vec::<isize>::with_capacity(len-i);
let mut past: Option<isize> = None;
for num in sequence_map.get(&(i-1)).unwrap() {
if let Some(past_unwrapped) = past {
new.push(past_unwrapped - num);
}
past = Some(*num);
}
let done = new.iter().all(|n| n == &0);
if done { new.push(0); }
sequence_map.insert(i, new);
if done { break }
else { i += 1; }
}
for j in (0..=i).rev() {
let diff = *sequence_map.get(&j).unwrap().last().unwrap();
let Some(modify_arr) = sequence_map.get_mut(&(j-1)) else { break };
modify_arr.push(*modify_arr.last().unwrap() - diff);
}
acc += *sequence_map[&0].last().unwrap() as i128;
}
acc.to_string()
}
}

View file

@ -7,7 +7,7 @@ use std::{
use clap::{Parser, Subcommand, ValueEnum};
use crate::{
day1::Day1, day2::Day2, day3::Day3, day4::Day4, day5::Day5, day6::Day6, day7::Day7, day8::Day8, utils::Day,
day1::Day1, day2::Day2, day3::Day3, day4::Day4, day5::Day5, day6::Day6, day7::Day7, day8::Day8, day9::Day9, utils::Day,
};
pub mod day1;
@ -18,6 +18,7 @@ pub mod day5;
pub mod day6;
pub mod day7;
pub mod day8;
pub mod day9;
pub mod fetcher;
pub mod utils;
@ -118,6 +119,7 @@ async fn main() {
hands: vec![],
}),
8 => Box::new(Day8 { input }),
9 => Box::new(Day9 { input }),
_ => panic!("Invalid day #"),
};
let start = std::time::Instant::now();
@ -177,6 +179,7 @@ async fn main() {
hands: vec![],
}),
8 => Box::new(Day8 { input }),
9 => Box::new(Day9 { input }),
_ => panic!("Invalid day #"),
};
let mut timings = Vec::<Duration>::new();