bendns' repos / aoc
heh
heh
Browse Source
bendn 2023-12-18
parent 5bb71df · commit 65bd15a
Diffstat
-rw-r--r--src/main.rs31
-rw-r--r--src/util.rs23
2 files changed, 38 insertions, 16 deletions
diff --git a/src/main.rs b/src/main.rs
index a406ec8..741f805 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -18,9 +18,9 @@ extern crate test;
pub mod util;
pub use util::prelude::*;
-pub fn p1(i: &str) -> u32 {
- let mut x = 0i32;
- let mut y = 0i32;
+pub fn p1(i: &str) -> u16 {
+ let mut x = 0i16;
+ let mut y = 0i16;
// boundary points, shoelace
let (b, a) = i.行().fold((0, 0), |(b, a), i| {
let d = unsafe { rint::<_, Dir>(C! { i[0] }) };
@@ -30,19 +30,20 @@ pub fn p1(i: &str) -> u32 {
(C! { i[2] } - b'0') * 10 + C! { i[3] } - b'0'
};
let (ox, oy) = (x, y);
- for _ in 0..c {
- (x, y) = match d {
- // y down
- Dir::N => (x, y + 1),
- Dir::E => (x + 1, y),
- Dir::S => (x, y - 1),
- Dir::W => (x - 1, y),
- };
- }
- (b + c as u32, a + ((x + ox) * (y - oy)))
+ (x, y) = match d {
+ // y down
+ Dir::N => (x, y + c as i16),
+ Dir::E => (x + c as i16, y),
+ Dir::S => (x, y - c as i16),
+ Dir::W => (x - c as i16, y),
+ };
+ (
+ b + c as u16,
+ a + ((x as i32 + ox as i32) * (y as i32 - oy as i32)),
+ )
});
// use shoelace formula to get the area, then use picks formula to count the number of inner points
- ((a.abs() / 2) as u32) + (1 + b / 2)
+ ((a.abs() / 2) as u16) + (1 + b / 2)
}
pub fn p2(i: &str) -> u64 {
@@ -57,7 +58,7 @@ pub fn p2(i: &str) -> u64 {
}
.as_ptr() as *const [u8; 6])
};
- let c = unsafe { 読む::hex(&dat[0..5]).unwrap_unchecked() };
+ let c = 読む::hex5(dat[0..5].try_into().unwrap());
let (ox, oy) = (x, y);
for _ in 0..c {
let d = 読む::hex_dig(dat[5]);
diff --git a/src/util.rs b/src/util.rs
index 874ab5a..d7b44a0 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -679,9 +679,30 @@ pub mod 読む {
}
}
}
+ const DIG: [u8; 256] = [
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ ];
pub fn hex_dig(b: u8) -> u8 {
- (b & 0xF) + 9 * (b >> 6)
+ DIG[b.nat()]
+ // (b & 0xF) + 9 * (b >> 6)
+ }
+
+ // i wonder if this is genericable
+ pub fn hex5([a, b, c, d, e]: [u8; 5]) -> u32 {
+ (hex_dig(a).widen().widen() << 16)
+ | (hex_dig(b).widen().widen() << 12)
+ | (hex_dig(c).widen().widen() << 8)
+ | (hex_dig(d).widen().widen() << 4)
+ | (hex_dig(e).widen().widen())
}
pub fn hex(mut d: &[u8]) -> Result<u32, ()> {