1218. Longest Arithmetic Subsequence of Given Difference
Medium
30 Points
Array
Hash Table
Dynamic Programming
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.
Examples
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
1218. Longest Arithmetic Subsequence of Given Difference
Medium
30 Points
Array
Hash Table
Dynamic Programming
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.
Examples
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
Longest Arithmetic Subsequence of Given Difference - Practice Coding | SlaveCode