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]
;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.
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
struct Solution;
impl Solution {
fn max_uncrossed_lines(a: Vec<i32>, b: Vec<i32>) -> i32 {
let n = a.len();
let m = b.len();
let mut dp = vec![vec![0; m + 1]; n + 1];
for i in 0..n {
for j in 0..m {
if a[i] == b[j] {
dp[i + 1][j + 1] = dp[i][j] + 1;
} else {
dp[i + 1][j + 1] = dp[i][j + 1].max(dp[i + 1][j]);
}
}
}
dp[n][m]
}
}
#[test]
fn test() {
let a = vec![1, 4, 2];
let b = vec![1, 2, 4];
let res = 2;
assert_eq!(Solution::max_uncrossed_lines(a, b), res);
let a = vec![2, 5, 1, 2, 5];
let b = vec![10, 5, 2, 1, 5, 2];
let res = 3;
assert_eq!(Solution::max_uncrossed_lines(a, b), res);
let a = vec![1, 3, 7, 1, 7, 5];
let b = vec![1, 9, 2, 5, 1];
let res = 2;
assert_eq!(Solution::max_uncrossed_lines(a, b), res);
}