Package g1201_1300.s1218_longest_arithmetic_subsequence_of_given_difference

Class Solution

java.lang.Object
g1201_1300.s1218_longest_arithmetic_subsequence_of_given_difference.Solution
public class Solution extends java.lang.Object
1218 - Longest Arithmetic Subsequence of Given Difference.

Medium

Given an integer array arr and an integer difference, return the length of the longest subsequence in arr which is an arithmetic sequence such that the difference between adjacent elements in the subsequence equals difference.

A subsequence is a sequence that can be derived from arr by deleting some or no elements without changing the order of the remaining elements.

Example 1:

Input: arr = [1,2,3,4], difference = 1

Output: 4

Explanation: The longest arithmetic subsequence is [1,2,3,4].

Example 2:

Input: arr = [1,3,5,7], difference = 1

Output: 1

Explanation: The longest arithmetic subsequence is any single element.

Example 3:

Input: arr = [1,5,7,8,5,3,4,2,1], difference = -2

Output: 4

Explanation: The longest arithmetic subsequence is [7,5,3,1].

Constraints:

  • 1 <= arr.length <= 105
  • -104 <= arr[i], difference <= 104

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    longestSubsequence(int[] arr, int difference)
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • longestSubsequence

      public int longestSubsequence(int[] arr, int difference)