https://segmentfault.com/a/1190000003819886
Given a sequence of integers, find the longest ascending subsequence (LIS) and return the length of the LIS.
The example gives [5,4,1,2,3], the LIS is [1,2,3], returns 3
Given [4,2,4,5,3,7], this LIS is [4,4,5,7], return 4
The challenge requires a time complexity of O(n^2) or O(nlogn)
Explain the definition of the longest ascending subsequence:
The longest ascending subsequence problem is to find a subsequence arranged from low to high as long as possible in an unordered given sequence, and this subsequence is not necessarily contiguous or unique.
https://en.wikipedia.org/wiki/Longest_common_subsequence_problem