Given an array nums of positive integers, return the longest possible
length of an array prefix of nums, such that it is possible to remove exactly
one element from this prefix so that every number that has appeared in it will
have the same number of occurrences.
If after removing one element there are no remaining elements, it's still considered that every appeared number has the same number of ocurrences (0).
Example 1:
Input: nums = [2,2,1,1,5,3,3,5] Output: 7 Explanation: For the subarray [2,2,1,1,5,3,3] of length 7, if we remove nums[4]=5, we will get [2,2,1,1,3,3], so that each number will appear exactly twice.
Example 2:
Input: nums = [1,1,1,2,2,2,3,3,3,4,4,4,5] Output: 13
Example 3:
Input: nums = [1,1,1,2,2,2] Output: 5
Example 4:
Input: nums = [10,2,8,9,3,8,1,5,2,3,7,6] Output: 8
Constraints:
2 <= nums.length <= 10^51 <= nums[i] <= 10^5