# We write the integers of A and B (in the order they are given) on two separate horizontal lines.
#
# Now, we may draw a straight line connecting two numbers A[i] and B[j] as long as A[i] == B[j], and the line we draw
# does not intersect any other connecting (non-horizontal) line.
#
# Return the maximum number of connecting lines we can draw in this way.
#
#
#
# Example 1:
#
#
# Input: A = [1,4,2], B = [1,2,4]
# Output: 2
# Explanation: We can draw 2 uncrossed lines as in the diagram.
# We cannot draw 3 uncrossed lines, because the line from A[1]=4 to B[2]=4 will intersect the line from A[2]=2 to B[
# 1]=2.
# Example 2:
#
# Input: A = [2,5,1,2,5], B = [10,5,2,1,5,2]
# Output: 3
# Example 3:
#
# Input: A = [1,3,7,1,7,5], B = [1,9,2,5,1]
# Output: 2
#
#
# Note:
#
# 1 <= A.length <= 500
# 1 <= B.length <= 500
# 1 <= A[i], B[i] <= 2000


class Solution(object):
    def maxUncrossedLines(self, A, B):
        """
        :type A: List[int]
        :type B: List[int]
        :rtype: int
        """
        L, M = len(A), len(B)
        lcs = [[0] * (L + 1) for _ in xrange(M + 1)]

        for i in xrange(M):
            for j in xrange(L):
                if A[j] == B[i]:
                    lcs[i + 1][j + 1] = lcs[i][j] + 1
                else:
                    lcs[i + 1][j + 1] = max(lcs[i][j + 1], lcs[i + 1][j])

        return lcs[M][L]


if __name__ == '__main__':
    print Solution().maxUncrossedLines([1, 4, 2], [1, 2, 4])
    print Solution().maxUncrossedLines([2, 5, 1, 2, 5], [10, 5, 2, 1, 5, 2])
    print Solution().maxUncrossedLines([1, 3, 7, 1, 7, 5], [1, 9, 2, 5, 1])
