https://leetcode.com/problems/longest-increasing-subsequence/

P[i] denotes the maximum length of increasing subsequence that ends with A[i].

class Solution:
    def lengthOfLIS(self, A: List[int]) -> int:
        if not A:
            return 0
        N=len(A)
        P=[1]*N
        for i in range(N):
            for j in range(i):
                if A[j]<A[i]:
                    P[i]=max(P[i],P[j]+1)
        return max(P)