# LeetCode 1035. 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 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:**

1 | Input: A = [1,4,2], B = [1,2,4] |

**Example 2:**

1 | Input: A = [2,5,1,2,5], B = [10,5,2,1,5,2] |

**Example 3:**

1 | Input: A = [1,3,7,1,7,5], B = [1,9,2,5,1] |

**Note:**

`1 <= A.length <= 500`

`1 <= B.length <= 500`

`1 <= A[i], B[i] <= 2000`

虽然题目看起来有点复杂，其实就是求最长公共子串的长度。连线互不交叉其实就是公共子串换了一种说法而已。

1 | class Solution { |