#![allow(dead_code)]
pub fn is_palindrome(s: String) -> bool {
if s.len() < 1 {
return true;
}
let s = s.into_bytes();
let mut i = 0;
let mut j = s.len() - 1;
while i < j {
if !s[i].is_ascii_alphanumeric() {
i += 1;
continue;
}
if !s[j].is_ascii_alphanumeric() {
j -= 1;
continue;
}
let c1 = s[i];
let c2 = s[j];
if c1.to_ascii_lowercase() != c2.to_ascii_lowercase() {
return false;
}
i += 1;
j -= 1;
}
true
}
pub fn is_palindrome2(s: String) -> bool {
let mut s1 = vec![];
for c in s.into_bytes() {
if c.is_ascii_alphanumeric() {
s1.push(c.to_ascii_lowercase());
}
}
let mut s2 = s1.clone();
s2.reverse();
s1 == s2
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test1() {
assert_eq!(is_palindrome(String::from(".,")), true);
assert_eq!(
is_palindrome(String::from("A man, a plan, a canal: Panama")),
true
);
assert_eq!(is_palindrome(String::from(".a")), true);
assert_eq!(is_palindrome(String::from("!!!")), true);
assert_eq!(is_palindrome(String::from("a.")), true);
}
#[test]
fn test2() {
assert_eq!(
is_palindrome2(String::from("A man, a plan, a canal: Panama")),
true
);
assert_eq!(is_palindrome2(String::from(".a")), true);
assert_eq!(is_palindrome2(String::from("a.")), true);
assert_eq!(is_palindrome2(String::from(".,")), true);
}
}