Number of Longest Increasing Subsequence

arraydynamic programmingbinary indexed tree

Problem Statement

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

Notice that the sequence has to be strictly increasing.

Examples

Example 1

Input: nums = [1,3,5,4,7]
Output: 2
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
The length of the longest increasing subsequence is 1, and there are 5 increasing subsequences of length 1, so output 5.

Constraints

1 <= nums.length <= 2000

-10 ^6 <= nums[i] <= 10 ^6

The answer is guaranteed to fit inside a 32-bit integer.

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicDynamic Programming