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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 FloatingWindowFallible {
Prewarming{
value : u32,
previous : [u32;2],
index : usize,
},
Ready{
value : u32,
previous : [u32;3],
index : usize,
},
}
impl FloatingWindowFallible {
fn try_get(&self) -> Option<u32> {
match self {
FloatingWindowFallible::Prewarming{..} => { None }
FloatingWindowFallible::Ready{value, ..} => { Some(*value) }
}
}
}
impl Default for FloatingWindowFallible {
fn default() -> Self {
FloatingWindowFallible::Prewarming{value:0,previous:[0;2],index:0}
}
}
impl Add<u32> for FloatingWindowFallible {
type Output = FloatingWindowFallible;
fn add(self, rhs : u32) -> FloatingWindowFallible {
match self {
FloatingWindowFallible::Prewarming{value, previous, index} if index < 2 => {
let mut arr = previous;
arr[index] = rhs;
FloatingWindowFallible::Prewarming{value: value + rhs, previous : arr, index: index + 1}
}
FloatingWindowFallible::Prewarming{value, previous, ..} => {
let arr = [previous[0], previous[1], rhs];
FloatingWindowFallible::Ready{value: value + rhs, previous : arr, index: 0}
}
FloatingWindowFallible::Ready{value, previous, index} => {
let mut arr = previous;
let old = arr[index];
arr[index] = rhs;
FloatingWindowFallible::Ready{value: (value + rhs) - old, previous : arr, index: (index + 1)%3}
}
}
}
}
#[aoc(day1, part2, AccumulatorTypeFallible)]
pub fn solve_part2_accumulator_type(input : &Vec<u32>) -> u32 {
struct Helper {
floating_window : FloatingWindowFallible,
prev : Option<u32>,
count : u32,
}
input.iter()
.fold(
Helper{floating_window : FloatingWindowFallible::default(), prev : None, count: 0},
|Helper{floating_window, prev, count}, i| {
let floating_window = floating_window + *i;
let curr = floating_window.try_get();
let count = count + prev.zip(curr).map(|(prev,curr)| if curr > prev {1} else {0}).unwrap_or(0);
Helper{floating_window, prev: curr, count}
}
).count
}
struct FloatingWindow {
value : u32,
previous : [u32;3],
index : usize,
}
impl Add<u32> for FloatingWindow {
type Output = FloatingWindow;
fn add(self, rhs : u32) -> FloatingWindow {
let mut arr = self.previous;
let old = arr[self.index];
arr[self.index] = rhs;
FloatingWindow{value : (self.value + rhs) - old, previous : arr, index: (self.index + 1)%3}
}
}
struct FloatingWindowInitializer {
value : u32,
previous : [u32;2],
index : usize,
}
type FloatingWindowInitializerStep = std::ops::ControlFlow<FloatingWindow,FloatingWindowInitializer>;
impl FloatingWindowInitializer {
fn add_step(self, input : &u32) -> FloatingWindowInitializerStep {
if self.index == 2 {
FloatingWindowInitializerStep::Break(FloatingWindow{ value : self.value + input, previous : [self.previous[0], self.previous[1], *input], index : 0})
}
else {
let mut arr = self.previous;
arr[self.index] = *input;
FloatingWindowInitializerStep::Continue(FloatingWindowInitializer{ value: self.value + input, previous : arr, index : self.index + 1})
}
}
}
impl Default for FloatingWindowInitializer {
fn default() -> Self {
Self{value : 0, previous : [0;2], index : 0}
}
}
#[aoc(day1, part2, AccumulatorTypeInfallible)]
pub fn solve_part2_accumulator_infallible(input : &Vec<u32>) -> Option<u32> {
let floating_window = match input.iter()
.try_fold(
FloatingWindowInitializer::default(),
FloatingWindowInitializer::add_step) {
FloatingWindowInitializerStep::Break(fw) => {Some(fw)}
FloatingWindowInitializerStep::Continue(_) => {None}
};
floating_window.map(|f| {
input.iter().skip(3).fold((f,0),|(f,c), u| {
let old = f.value;
let f = f+*u;
if f.value > old {
(f,c+1)
} else {
(f,c)
}}).1
}
)
}
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