g1001_1100.s1027_longest_arithmetic_subsequence

Class Solution

java.lang.Object

g1001_1100.s1027_longest_arithmetic_subsequence.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 Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	longestArithSeqLength(int[] nums)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

longestArithSeqLength

public int longestArithSeqLength(int[] nums)