Strings A and B are K-similar (for some non-negative integer K) if we can swap the positions of two letters in A exactly K times so that the resulting string equals B.
Given two anagrams A and B, return the smallest K for which A and B are K-similar.
Example 1:
Input: A = "ab", B = "ba" Output: 1
Example 2:
Input: A = "abc", B = "bca" Output: 2
Example 3:
Input: A = "abac", B = "baca" Output: 2
Example 4:
Input: A = "aabc", B = "abca" Output: 2
Note:
<li><code>1 <= A.length == B.length <= 20</code></li>
<li><code>A</code> and <code>B</code> contain only lowercase letters from the set <code>{'a', 'b', 'c', 'd', 'e', 'f'}</code></li>