<p>Given an integer array&nbsp;<code>nums</code>, return <em>the number of longest increasing subsequences.</em></p>

<p><strong>Notice</strong> that the sequence has to be <strong>strictly</strong> increasing.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

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

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,2,2,2,2]
<strong>Output:</strong> 5
<strong>Explanation:</strong> The length of the longest increasing subsequence is 1, and there are 5 increasing subsequences of length 1, so output 5.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 2000</code></li>
	<li><code>-10<sup>6</sup> &lt;= nums[i] &lt;= 10<sup>6</sup></code></li>
	<li>The answer is guaranteed to fit inside a 32-bit integer.</li>
</ul>

class Solution{
    public:
    vector<int> dp;
    vector<int> num;
    vector<int> countseq;
    int findNumberOfLIS(vector<int>& nums){
        num = nums;
        for(int i = 0; i < nums.size(); i++){
            dp.push_back(1);
            countseq.push_back(1);
        }
        for(int i = 1; i < nums.size(); i++){
            f(i);
        }
        int count = 0;
        int max = 1;
        countseq[0] = 1;
        for(int i = 0; i < dp.size(); i++){
            if(dp[i] > max){
                max = dp[i];
                count = countseq[i];
            }
            else if(dp[i] == max){
                count += countseq[i];
            }
        }
        return count;
    }
    void f(int index){
        int greatest = 1;
        int count = 1;
        for(int i = index - 1; i >= 0 ; i--){
            if(num[index] > num[i]){
                if(dp[i] + 1 > greatest){
                    greatest = dp[i] + 1;
                    count = countseq[i];
                }
                else if(dp[i] + 1 == greatest){
                    count += countseq[i];
                }
            }
        }
        dp[index] = greatest;
        countseq[index] = count;
        return;
    }
};
16700