2021: day02: quick solve

This commit is contained in:
Antoine Martin 2021-12-02 10:25:59 +01:00
parent 3aa37aff10
commit 0eed53749c
4 changed files with 1089 additions and 1 deletions

1000
aoc2021/input/day02.txt Normal file

File diff suppressed because it is too large Load diff

86
aoc2021/src/day02.rs Normal file
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@ -0,0 +1,86 @@
use std::fmt::Write;
use anyhow::{bail, Result};
const INPUT: &str = include_str!("../input/day02.txt");
pub fn run() -> Result<String> {
let mut res = String::with_capacity(128);
writeln!(res, "part 1: {}", part1(INPUT)?)?;
writeln!(res, "part 2: {}", part2(INPUT)?)?;
Ok(res)
}
fn part1(input: &str) -> Result<u64> {
let commands = input
.lines()
.map(str::parse::<Command>)
.collect::<Result<Vec<_>>>()?;
let mut horizontal_pos = 0;
let mut depth = 0;
for c in commands {
match c {
Command::Forward(dx) => horizontal_pos += dx,
Command::Up(dz) => depth -= dz,
Command::Down(dz) => depth += dz,
}
}
Ok(depth * horizontal_pos)
}
fn part2(input: &str) -> Result<u64> {
let commands = input
.lines()
.map(str::parse::<Command>)
.collect::<Result<Vec<_>>>()?;
let mut horizontal_pos = 0;
let mut depth = 0;
let mut aim = 0;
for c in commands {
match c {
Command::Forward(dx) => {
horizontal_pos += dx;
depth += aim * dx;
}
Command::Up(dz) => {
aim -= dz;
}
Command::Down(dz) => {
aim += dz;
}
}
}
Ok(depth * horizontal_pos)
}
enum Command {
Forward(u64),
Up(u64),
Down(u64),
}
impl std::str::FromStr for Command {
type Err = anyhow::Error;
fn from_str(s: &str) -> Result<Self> {
let mut split = s.split(' ');
let word = split.next().unwrap();
let number = split.next().unwrap();
let number = number.parse()?;
Ok(match word {
"forward" => Self::Forward(number),
"up" => Self::Up(number),
"down" => Self::Down(number),
_ => bail!("unkown command"),
})
}
}

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@ -1,3 +1,4 @@
#![warn(clippy::explicit_iter_loop, clippy::redundant_closure_for_method_calls)] #![warn(clippy::explicit_iter_loop, clippy::redundant_closure_for_method_calls)]
pub mod day01; pub mod day01;
pub mod day02;

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@ -3,9 +3,10 @@ use anyhow::Result;
use aoc::DayFunc; use aoc::DayFunc;
use aoc2021::day01; use aoc2021::day01;
use aoc2021::day02;
fn main() -> Result<()> { fn main() -> Result<()> {
let days: &[DayFunc] = &[day01::run]; let days: &[DayFunc] = &[day01::run, day02::run];
aoc::run(days) aoc::run(days)
} }