3960. Frequency Balance Subarray

You are given an integer array ​​​​​​​nums. Define a frequency balance subarray as follows: - 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 t