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nora 2024-12-07 15:02:10 +01:00
parent 3e9ff4ded0
commit 4ca45bedfc
1 changed files with 14 additions and 4 deletions
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18
2024/day07/src/lib.rs
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@ -175,16 +175,26 @@ fn part2_parsing(input: &str) -> u64 {
values.clear(); values.clear();
let (result, values_str) = line.split_once(": ").unwrap(); let (result, values_str) = line.split_once(": ").unwrap();
let result = parse_unwrap(result); let result = parse_unwrap(result);
values.extend(values_str.split(' ').map(|val| (val, parse_unwrap(val)))); values.extend(values_str.split(' ').map(str::as_bytes).map(|vals| {
let parse1 = |i| (vals[i] - b'0') as u64;
(
10_u64.pow(vals.len() as u32),
match vals.len() {
1 => parse1(0),
2 => parse1(0) * 10 + parse1(1),
3 => parse1(0) * 100 + parse1(1) * 10 + parse1(2),
_ => unreachable!(),
},
)
}));
fn does_work(values: &[(&str, u64)], result: u64) -> bool { fn does_work(values: &[(u64, u64)], result: u64) -> bool {
if values.len() == 1 { if values.len() == 1 {
return values[0].1 == result; return values[0].1 == result;
} }
let (l_str, l) = *values.last().unwrap(); let (thousand, l) = *values.last().unwrap();
let next = &values[..(values.len() - 1)]; let next = &values[..(values.len() - 1)];
let thousand = 10_u64.pow(l_str.len() as u32);
let concat_works = result % thousand == l; let concat_works = result % thousand == l;
let mul_works = result % l == 0; let mul_works = result % l == 0;