https://leetcode.com/problems/number-of-longest-increasing-subsequence/description/

class Solution {
public:
    int findNumberOfLIS(vector<int>& nums) {
        vector<int> dp(nums.size(), 1);
        vector<int> ct(nums.size(), 1);
        int maxLen = 1;
        for(int i=1; i<nums.size(); i++){
            for(int j=0; j<i; j++){
                if(nums[i]>nums[j]){
                    if(dp[i] < dp[j]+1){
                        dp[i] = dp[j]+1;
                        ct[i] = ct[j];
                    }
                    else if (dp[i]==dp[j]+1){
                        ct[i] += ct[j];
                    }
                }
            }
            maxLen = max(maxLen, dp[i]);
        }
        int ret = 0;
        for(int i=0; i<ct.size(); i++) if(dp[i]==maxLen) ret+=ct[i];
        return ret;
    }
};