If the subarray contains only one distinct value, it is frequency balanced.
Otherwise, there must exist a positive integer f such that every distinct value in the subarray occurs either f or 2 * f times, and both frequencies occur among the distinct values.
Return an integer denoting the length of the longest frequency balance subarray.
Example 1:
Input:nums = [1,2,2,1,2,3,3,3]
Output:5
Explanation:
The longest frequency balance subarray is [2, 1, 2, 3, 3].
The elements that appear most frequently are 2 and 3, both appearing twice.
The remaining element 1 appears once, meeting the requirements.
Example 2:
Input:nums = [5,5,5,5]
Output:4
Explanation:
The longest frequency balance subarray is [5, 5, 5, 5].
The element that appears most frequently is 5.
There are no other elements meeting the requirements.
Example 3:
Input:nums = [1,2,3,4]
Output:1
Explanation:
Since all elements appear only once, the length of the longest frequency balance subarray is 1.