26 lines
719 B
Rust
26 lines
719 B
Rust
|
use std::env::var as envvar;
|
||
|
|
use std::path::Path;
|
||
|
|
use std::fs;
|
||
|
|
|
||
|
|
const ASCII_UPPER_A: u8 = 65;
|
||
|
|
const ASCII_LOWER_A: u8 = 97;
|
||
|
|
const ASCII_0: u8 = 48;
|
||
|
|
|
||
|
|
pub fn day_input(day: u8) -> String {
|
||
|
|
let home = &envvar("HOME").unwrap();
|
||
|
|
let home_path = Path::new(home);
|
||
|
|
let path_buf = home_path.join(format!("./.cache/aoc2021/{0}.input", day));
|
||
|
|
let file_path = path_buf.to_str().unwrap();
|
||
|
|
fs::read_to_string(file_path).unwrap()
|
||
|
|
}
|
||
|
|
|
||
|
|
pub const fn hex_val(c: char) -> Result<u8, &'static str> {
|
||
|
|
match c {
|
||
|
|
'A'..='F' => Ok(c as u8 - ASCII_UPPER_A + 10),
|
||
|
|
'a'..='f' => Ok(c as u8 - ASCII_LOWER_A + 10),
|
||
|
|
'0'..='9' => Ok(c as u8 - ASCII_0 as u8),
|
||
|
|
_ => Err("invalid hex char"),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|