An element x of an integer array arr of length m is dominant if more than half the elements of arr have a value of x.
You are given a 0-indexed integer array nums of length n with one dominant element.
You can split nums at an index i into two arrays nums[0, ..., i] and nums[i + 1, ..., n - 1], but the split is only valid if:
0 <= i < n - 1nums[0, ..., i], andnums[i + 1, ..., n - 1]have the same dominant element.
Here,nums[i, ..., j]denotes the subarray ofnumsstarting at indexiand ending at indexj, both ends being inclusive. Particularly, ifj < ithennums[i, ..., j]denotes an empty subarray.
Return the minimum index of a valid split. If no valid split exists, return -1.
Example 1:
Input: nums = [1,2,2,2]
Output: 2Explanation: We can split the array at index 2 to obtain arrays [1,2,2] and [2].
In array [1,2,2], element 2 is dominant since it occurs twice in the array and 2 * 2 > 3.
In array [2], element 2 is dominant since it occurs once in the array and 1 * 2 > 1.
Both [1,2,2] and [2] have the same dominant element as nums, so this is a valid split.
It can be shown that index 2 is the minimum index of a valid split.
Example 2:
Input: nums = [2,1,3,1,1,1,7,1,2,1]
Output: 4Explanation: We can split the array at index 4 to obtain arrays [2,1,3,1,1] and [1,7,1,2,1].
In array [2,1,3,1,1], element 1 is dominant since it occurs thrice in the array and 3 * 2 > 5.
In array [1,7,1,2,1], element 1 is dominant since it occurs thrice in the array and 3 * 2 > 5.
Both [2,1,3,1,1] and [1,7,1,2,1] have the same dominant element as nums, so this is a valid split.
It can be shown that index 4 is the minimum index of a valid split.
Example 3:
Input: nums = [3,3,3,3,7,2,2]
Output: -1Explanation: It can be shown that there is no valid split.
Constraints:
1 <= nums.length <= 100,0001 <= nums[i] <= 1,000,000,000numshas exactly one dominant element.