Leetcode - Uncrossed Lines

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

We write the integers of A and B (in the order they are given) on two separate horizontal lines.

Now, we may draw connecting lines: a straight line connecting two numbers A[i] and B[j] such that:

• A[i] == B[j];
• The line we draw does not intersect any other connecting (non-horizontal) line.

Note that a connecting lines cannot intersect even at the endpoints: each number can only belong to one connecting 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.

func maxUncrossedLines(A []int, B []int) int {
    m := len(A)
    n := len(B)
    dp := make([][]int, m+1)
    for i := 0; i < len(dp); i++ {
        dp[i] = make([]int, n+1)
    }
    for i := m-1; i >= 0; i-- {
        for j := n-1; j >= 0; j-- {
            if A[i] == B[j] {
                dp[i][j] = dp[i+1][j+1] + 1
            } else {
                dp[i][j] = max(dp[i][j+1], dp[i+1][j])
            }
        }
    }
    return dp[0][0]
}

func max(a, b int) int {
    if a > b {
        return a
    }
    return b
}

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