1035. Uncrossed Lines

https://leetcode.com/problems/uncrossed-lines/

Think dynamic programming. Given an oracle dp(i,j) that tells us how many lines A[i:], B[j:] [the sequence A[i], A[i+1], ... and B[j], B[j+1], ...] are uncrossed, can we write this as a recursion?

2   5   1    2    5
10  5   2    1    5    2

class Solution:
    def maxUncrossedLines(self, A: List[int], B: List[int]) -> int:
        m = len(A)
        n = len(B)
        dp = [[0]*(n+1) for _ in range(m+1)]
        for i in range(1,m+1):
            for j in range(1,n+1):
                if A[i-1] == B[j-1]:
                    dp[i][j] = dp[i-1][j-1]+1
                else:
                    dp[i][j] = max(dp[i][j-1],dp[i-1][j])
        return dp[m][n]