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- add problem 3518 implementation - add build configuration with debug and release modes - add test cases and examples - add makefile for problem-specific build workflow
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3518. Smallest Palindromic Rearrangement II
You are given a string s and an integer k.
Return the k-th palindromic 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 <= 104sconsists of lowercase English letters.sis guaranteed to be palindromic.1 <= k <= 106