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129 lines
2.4 KiB

4 years ago
use std::{
ops::RangeInclusive,
str,
fmt,
error,
};
use smallmap::Map;
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Policy
{
letter: char,
rep: RangeInclusive<usize>,
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct PolicyV2
{
letter: char,
i: usize,
j: usize,
}
impl PolicyV2
{
#[inline] pub fn validate_str(&self, s: &str) -> bool
{
self.validate(s.chars().collect::<Vec<_>>())
}
pub fn validate(&self, vec: impl AsRef<[char]>) -> bool
{
let vec = vec.as_ref();
if self.i>=vec.len() || self.j>=vec.len() { return false; }
match (vec[self.i], vec[self.j]) {
(l, ll) if l == ll => false,
(x, _) | (_, x) if x == self.letter => true,
_ => false,
}
}
}
impl Policy
{
#[inline] pub fn into_v2(self) -> PolicyV2
{
PolicyV2
{
letter: self.letter,
i: (*self.rep.start())-1,
j: (*self.rep.end())-1,
}
}
#[inline(always)] pub fn validate_str(&self, s: impl AsRef<str>) -> bool
{
self.validate(s.as_ref().chars())
}
pub fn validate(&self, chars: impl IntoIterator<Item=char>) -> bool
{
let map: Map<char, usize> = {
let chars = chars.into_iter();
let mut mp = Map::new();
for ch in chars
{
let cnt = mp.entry(ch).or_insert(0);
*cnt += 1;
}
mp
};
if let Some(n) = map.get(&self.letter)
{
self.rep.contains(n)
} else {
false
}
}
}
impl fmt::Display for Policy
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
{
write!(f, "{}-{} {}", self.rep.start(), self.rep.end(), self.letter)
}
}
impl str::FromStr for Policy
{
type Err = FromStrError;
fn from_str(s: &str) -> Result<Self, Self::Err>
{
let mut first = s.split('-');
let num1 = first.next().ok_or(FromStrError)?;
let (num2, letter) = {
let num2_rest = first.next().ok_or(FromStrError)?;
let mut rest = num2_rest.split(' ');
(rest.next().ok_or(FromStrError)?, rest.next().ok_or(FromStrError)?)
};
Ok(Self{
letter: letter.chars().next().ok_or(FromStrError)?,
rep: (num1.parse()?)..=(num2.parse()?),
})
}
}
#[derive(Debug)]
pub struct FromStrError;
impl From<std::num::ParseIntError> for FromStrError
{
#[inline] fn from(_: std::num::ParseIntError) -> Self
{
Self
}
}
impl error::Error for FromStrError{}
impl fmt::Display for FromStrError
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
{
write!(f, "failed to parse policy rule")
}
}