You are given a palindromic string s and an integer k. Retu...

Prompt

You are given a palindromic string s and an integer k. Return the k-th lexicographically smallest palindromic permutation of s. If there are fewer than k distinct palindromic permutations, return an empty string. Note: Different rearrangements that yield the same palindromic string are considered identical and are counted once. Example 1: Input: s = "abba", k = 2 Output: "baab" Explanation: The two distinct palindromic rearrangements of "abba" are "abba" and "baab". Lexicographically, "abba" comes before "baab". Since k = 2, the output is "baab". Example 2: Input: s = "aa", k = 2 Output: "" Explanation: There is only one palindromic rearrangement: "aa". The output is an empty string since k = 2 exceeds the number of possible rearrangements. Example 3: Input: s = "bacab", k = 1 Output: "abcba" Explanation: The two distinct palindromic rearrangements of "bacab" are "abcba" and "bacab". Lexicographically, "abcba" comes before "bacab". Since k = 1, the output is "abcba". Constraints: 1 <= s.length <= 104 s consists of lowercase English letters. s is guaranteed to be palindromic. 1 <= k <= 106