Given a non-empty string s and an integer k, rearrange the string such that the same characters are at least distance k from each other.
All input strings are given in lowercase letters. If it is not possible to rearrange the
string, return an empty string "".
Example 1:
Input: s = "aabbcc", k = 3 Output: "abcabc" Explanation: The same letters are at least distance 3 from each other.
Example 2:
Input: s = "aaabc", k = 3 Output: "" Explanation: It is not possible to rearrange the string.
Example 3:
Input: s = "aaadbbcc", k = 2 Output: "abacabcd" Explanation: The same letters are at least distance 2 from each other.