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:
"abba"
are "abba"
and "baab"
."abba"
comes before "baab"
. Since k = 2
, the output is "baab"
.Example 2:
Input: s = "aa", k = 2
Output: ""
Explanation:
"aa"
.k = 2
exceeds the number of possible rearrangements.Example 3:
Input: s = "bacab", k = 1
Output: "abcba"
Explanation:
"bacab"
are "abcba"
and "bacab"
."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