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|
use aoc_runner_derive::*;
use std::str::FromStr;
use std::ops::Add;
#[aoc_generator(day1)]
pub fn input_generator<'c>(input : &'c str) -> Vec<u32>{
input.lines().map(u32::from_str).map(Result::unwrap).collect()
}
#[aoc(day1, part1, InternalState)]
pub fn solve_part1(input : &Vec<u32>) -> u32 {
struct Helper {
count : u32,
prev : u32,
}
input.iter().fold(Helper{count:0,prev:u32::MAX},|x ,curr| -> Helper {if curr > &x.prev {Helper{count : x.count + 1, prev : *curr}} else {Helper{count : x.count, prev : *curr}}}).count
}
#[aoc(day1, part1, Iterators)]
pub fn solve_part1_iterators(input : &Vec<u32>) -> usize {
input.iter().skip(1).zip(input.iter()).filter(|(new, old)| new > old).count()
}
#[aoc(day1, part2, InternalState)]
pub fn solve_part2(input : &Vec<u32>) -> usize {
let floating_window :u32 = input.iter().take(3).sum();
input.iter().skip(3).zip(input.iter()).scan(floating_window, |floating_window, (new, old)| {
let prev_window = *floating_window;
*floating_window = (*floating_window + *new) - *old;
Some((*floating_window, prev_window))
}).filter(|(new, old)| new > old).count()
}
#[aoc(day1,part2, DumbLoop)]
pub fn solve_part2_dumb_loop(input : &Vec<u32>) -> usize {
if input.len() < 3 {
0
}
else {
let mut floating_window = input[0]+input[1]+input[2];
let mut sum = 0;
for index in 3..input.len() {
let old = floating_window;
floating_window = (floating_window + input[index]) - input[index -3];
if floating_window > old {
sum = sum + 1;
}
}
sum
}
}
#[aoc(day1, part2, Iterators)]
pub fn solve_part2_iterators(input : &Vec<u32>) -> usize {
let sliding_window = input.iter().skip(2).zip(input.iter().skip(1)).zip(input.iter())
.map(|((third, second), first)| third + second + first);
let old_window = sliding_window.clone();
let sliding_window = sliding_window.skip(1);
sliding_window.zip(old_window).filter(|(new, old)| new > old).count()
}
enum FloatingWindow {
Prewarming{
value : u32,
previous : [u32;2],
index : usize,
},
Ready{
value : u32,
previous : [u32;3],
index : usize,
},
}
impl FloatingWindow {
fn try_get(&self) -> Option<u32> {
match self {
FloatingWindow::Prewarming{..} => { None }
FloatingWindow::Ready{value, ..} => { Some(*value) }
}
}
}
impl Default for FloatingWindow {
fn default() -> Self {
FloatingWindow::Prewarming{value:0,previous:[0;2],index:0}
}
}
impl Add<u32> for FloatingWindow {
type Output = FloatingWindow;
fn add(self, rhs : u32) -> FloatingWindow {
match self {
FloatingWindow::Prewarming{value, previous, index} if index < 2 => {
let mut arr = previous;
arr[index] = rhs;
FloatingWindow::Prewarming{value: value + rhs, previous : arr, index: index + 1}
}
FloatingWindow::Prewarming{value, previous, index} => {
let arr = [previous[0], previous[1], rhs];
FloatingWindow::Ready{value: value + rhs, previous : arr, index: 0}
}
FloatingWindow::Ready{value, previous, index} => {
let mut arr = previous;
let old = arr[index];
arr[index] = rhs;
FloatingWindow::Ready{value: (value + rhs - old), previous : arr, index: (index + 1)%3}
}
}
}
}
#[aoc(day1, part2, AccumulatorType)]
pub fn solve_part2_accumulator_type(input : &Vec<u32>) -> u32 {
struct Helper {
floating_window : FloatingWindow,
prev : Option<u32>,
count : u32,
}
input.iter()
.fold(
Helper{floating_window : FloatingWindow::default(), prev : None, count: 0},
|Helper{floating_window, prev, count}, i| {
let prev = floating_window.try_get();
let floating_window = floating_window + *i;
let curr = floating_window.try_get();
let count = count + prev.zip(curr).and_then(|(prev,curr)| (curr > prev).then(|| 1)).unwrap_or(0);
Helper{floating_window, prev, count}
}
).count
}
|
