Class Solution


  • public class Solution
    extends Object
    1027 - Longest Arithmetic Subsequence.

    Medium

    Given an array nums of integers, return the length of the longest arithmetic subsequence in nums.

    Recall that a subsequence of an array nums is a list nums[i1], nums[i2], …, nums[ik] with 0 <= i1 < i2 < … < ik <= nums.length - 1, and that a sequence seq is arithmetic if seq[i+1] - seq[i] are all the same value (for 0 <= i < seq.length - 1).

    Example 1:

    Input: nums = [3,6,9,12]

    Output: 4

    Explanation: The whole array is an arithmetic sequence with steps of length = 3.

    Example 2:

    Input: nums = [9,4,7,2,10]

    Output: 3

    Explanation: The longest arithmetic subsequence is [4,7,10].

    Example 3:

    Input: nums = [20,1,15,3,10,5,8]

    Output: 4

    Explanation: The longest arithmetic subsequence is [20,15,10,5].

    Constraints:

    • 2 <= nums.length <= 1000
    • 0 <= nums[i] <= 500
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • longestArithSeqLength

        public int longestArithSeqLength​(int[] nums)