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impl Solution {
fn check_odd(s: &String, i: i32) -> (i32, i32, i32) {
let mut r = 0;
loop {
let next = r + 1;
if i - next < 0
|| i + next >= s.len() as i32
|| s.as_bytes()[(i-next) as usize] != s.as_bytes()[(i+next) as usize] {
break;
}
r = next;
}
let len = 2 * r + 1;
let start = i - r;
let end = i + r;
(len, start, end)
}
fn check_even(s: &String, i: i32) -> (i32, i32, i32) {
let mut r = 0;
loop {
let next = r + 1;
if i - next + 1 < 0
|| i + next >= s.len() as i32
|| s.as_bytes()[(i-next+1) as usize] != s.as_bytes()[(i+next) as usize] {
break;
}
r = next;
}
let len = 2 * r;
let start = i - r + 1;
let end = i + r;
(len, start, end)
}
fn check_palindrome_len(s: &String, i: i32) -> (i32, i32, i32) {
let (len1, start1, end1) = Self::check_odd(s, i);
let (len2, start2, end2) = Self::check_even(s, i);
if len2 > len1 {
(len2, start2, end2)
} else {
(len1, start1, end1)
}
}
pub fn longest_palindrome(s: String) -> String {
let mut maxpalinlen = -1;
let mut start: i32 = 0;
let mut end: i32 = 0;
for i in 0..s.len() {
let (palin_len, pstart, pend) = Self::check_palindrome_len(&s, i as i32);
if palin_len > maxpalinlen {
maxpalinlen = palin_len;
start = pstart;
end = pend;
}
}
s[start as usize ..(end + 1) as usize].to_string()
}
}
struct Solution {}
fn main () {
println!("{}", Solution::longest_palindrome("babad".to_string()));
println!("{}", Solution::longest_palindrome("cbbd".to_string()));
}
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