Given an integer array nums, return the number of longest increasing subsequences.
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:
0 <= nums.length <= 2000-106 <= nums[i] <= 106public int findNumberOfLIS(int[] nums) { int n = nums.length, res = 0, max_len = 0; int[] len = new int[n], cnt = new int[n]; for(int i = 0; i<n; i++){ len[i] = cnt[i] = 1; for(int j = 0; j <i ; j++){ if(nums[i] > nums[j]){ if(len[i] == len[j] + 1)cnt[i] += cnt[j]; if(len[i] < len[j] + 1){ len[i] = len[j] + 1; cnt[i] = cnt[j]; } } } if(max_len == len[i])res += cnt[i]; if(max_len < len[i]){ max_len = len[i]; res = cnt[i]; } } return res; }
https://leetcode.com/problems/number-of-longest-increasing-subsequence/discuss/107293/JavaC%2B%2B-Simple-dp-solution-with-explanation
673. Number of Longest Increasing Subsequence
原文：https://www.cnblogs.com/wentiliangkaihua/p/13905653.html