Given an integer array `nums`, return the number of longest increasing subsequences.

Notice that the sequence has to be strictly increasing.

Example 1:

    Input: nums = [1,3,5,4,7]
    Output: 2
    Explanation: The two longest increasing subsequences are [1, 3, 4, 7] and [1, 3, 5, 7].

Example 2:

    Input: nums = [2,2,2,2,2]
    Output: 5
    Explanation: The length of longest continuous increasing subsequence is 1, and there are 5 subsequences' length is 1, so output 5.

Constraints:

- `1 <= nums.length <= 2000`
- `-106 <= nums[i] <= 106`