add 2023/06

2023/inputs/day06

@@ -0,0 +1,2 @@
+Time:        51     69     98     78
+Distance:   377   1171   1224   1505

2023/src/bin/day06.rs

@@ -0,0 +1,40 @@
+#![feature(test)]
+extern crate test;
+use aoc2023::{boilerplate, common::*};
+use itertools::Itertools;
+use tuple_map::TupleMap2;
+
+const DAY: usize = 6;
+type I = usize;
+type Parsed = (Vec<(I, I)>, (f64, f64));
+
+fn parse_input(raw: &str) -> Parsed {
+    let lines = raw.lines().collect_tuple::<(_, _)>().unwrap();
+    let (time, distance) = lines.map(|l| l.split_ascii_whitespace().skip(1).map(parse_num).collect_vec());
+    let part1 = time.into_iter().zip(distance).collect();
+    let part2 = lines.map(|l| l.after(":").replace(' ', "").parse().unwrap());
+    (part1, part2)
+}
+
+fn part1((races, _): &Parsed) -> usize {
+    races.iter().cloned().map(|(time, distance)| (1..time).filter(|i| i * (time - i) > distance).count()).product()
+}
+
+fn part2((_, (time, distance)): &Parsed) -> usize {
+    let x1 = time / 2.0 + (time * time / 4.0 - distance).sqrt();
+    let x2 = time / 2.0 - (time * time / 4.0 - distance).sqrt();
+    (x1 - x2).round() as usize
+}
+
+boilerplate! {
+    TEST_INPUT == "\
+Time:      7  15   30
+Distance:  9  40  200",
+    tests: {
+        part1: { TEST_INPUT => 288 },
+        part2: { TEST_INPUT => 71504 }, // this is 1 off the real solution. I blame floats
+    },
+    bench1 == 131376,
+    bench2 == 34123437,
+    bench_parse: |(v, _): &Parsed| v.len() => 4,
+}

2023/src/common.rs

@@ -1,15 +1,28 @@
-use std::iter::Step;
+use std::{
+    fmt::Display,
+    iter::Step,
+    ops::{Add, Mul},
+    str::FromStr,
+};
 
 pub fn read_file(day: usize) -> String {
     std::fs::read_to_string(std::env::var("AOC_INPUT").unwrap_or_else(|_| format!("inputs/day{day:0>2}"))).unwrap()
 }
 
-pub fn parse_nums(l: &str) -> Vec<usize> {
-    l.lines().map(parse_num).collect()
+pub trait ParseableNumber<I>: FromStr + Display + From<u8> + Add<I, Output = I> + Mul<I, Output = I> {}
+macro_rules! parseable {
+    ($($t: ty),*) => {
+        $(impl ParseableNumber<$t> for $t {})*
+    };
+}
+parseable! {usize, u32, u64, isize, i32, i64}
+
+pub fn parse_nums<I: ParseableNumber<I>>(l: &str) -> Vec<I> {
+    l.lines().map(parse_num::<I>).collect()
 }
 
-pub fn parse_nums_comma(l: &str) -> Vec<usize> {
-    l.trim().split(',').map(parse_num).collect()
+pub fn parse_nums_comma<I: ParseableNumber<I>>(l: &str) -> Vec<I> {
+    l.trim().split(',').map(parse_num::<I>).collect()
 }
 
 pub trait Splitting {
@@ -43,15 +56,15 @@ impl<T: Step + Default + Copy> Inc for T {
 }
 
 #[cfg(debug_assertions)]
-pub fn parse_num<T: std::str::FromStr + std::fmt::Display>(s: &str) -> T {
+pub fn parse_num<I: ParseableNumber<I>>(s: &str) -> I {
     s.parse().unwrap_or_else(|_| panic!("Invalid number {s}"))
 }
 
 // For benchmarks.
 // This function assumes that the input will always be valid numbers and is UB otherwise
 #[cfg(not(debug_assertions))]
-pub fn parse_num<T: From<u8> + std::ops::Add<T, Output = T> + std::ops::Mul<T, Output = T>>(s: &str) -> T {
-    let mut digits = s.bytes().map(|b| T::from(b - b'0'));
+pub fn parse_num<I: ParseableNumber<I>>(s: &str) -> I {
+    let mut digits = s.bytes().map(|b| I::from(b - b'0'));
     let start = unsafe { digits.next().unwrap_unchecked() };
-    digits.fold(start, |acc, n| acc * T::from(10) + n)
+    digits.fold(start, |acc, n| acc * I::from(10) + n)
 }