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 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 and Description
Solution()

Method Summary

Modifier and Type	Method and 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 Detail

Solution

public Solution()

Method Detail

longestSubsequence

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