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mod s0001_two_sum;
mod s0009_palindrome_number;
mod s0020_valid_parentheses;
mod s2697_lexicographically_smallest_palindrome;

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/**
* [2697] Lexicographically Smallest Palindrome
*
* You are given a string <code node="[object Object]">s consisting of lowercase English letters, and you are allowed to perform operations on it. In one operation, you can replace a character in <code node="[object Object]">s with another lowercase English letter.
* Your task is to make <code node="[object Object]">s a palindrome with the minimum number of operations possible. If there are multiple palindromes that can be <meta charset="utf-8" />made using the minimum number of operations, <meta charset="utf-8" />make the lexicographically smallest one.
* A string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b.
* Return the resulting palindrome string.
*
* <strong class="example">Example 1:
*
* Input: s = "egcfe"
* Output: "efcfe"
* Explanation: The minimum number of operations to make "egcfe" a palindrome is 1, and the lexicographically smallest palindrome string we can get by modifying one character is "efcfe", by changing 'g'.
*
* <strong class="example">Example 2:
*
* Input: s = "abcd"
* Output: "abba"
* Explanation: The minimum number of operations to make "abcd" a palindrome is 2, and the lexicographically smallest palindrome string we can get by modifying two characters is "abba".
*
* <strong class="example">Example 3:
*
* Input: s = "seven"
* Output: "neven"
* Explanation: The minimum number of operations to make "seven" a palindrome is 1, and the lexicographically smallest palindrome string we can get by modifying one character is "neven".
*
*
* Constraints:
*
* 1 <= s.length <= 1000
* s consists of only lowercase English letters.
*
*/
pub struct Solution {}
// problem: https://leetcode.cn/problems/lexicographically-smallest-palindrome/
// discuss: https://leetcode.cn/problems/lexicographically-smallest-palindrome/discuss/?currentPage=1&orderBy=most_votes&query=
// submission codes start here
use std::cmp::min;
impl Solution {
pub fn make_smallest_palindrome(s: String) -> String {
let mut result : Vec<u8> = s.bytes().collect();
let mut left = 0;
let mut right = result.len() - 1;
while left < right {
if result[left] != result[right] {
let value = min(result[left], result[right]);
result[left] = value;
result[right] = value;
}
left = left + 1;
right = right - 1;
}
String::from_utf8(result).unwrap()
}
}
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_2697() {
assert_eq!(String::from("efcfe"),
Solution::make_smallest_palindrome(String::from("egcfe")));
assert_eq!(String::from("abba"),
Solution::make_smallest_palindrome(String::from("abcd")));
assert_eq!(String::from("neven"),
Solution::make_smallest_palindrome(String::from("seven")));
}
}