Package g1901_2000.s1911_maximum_alternating_subsequence_sum

Class Solution

java.lang.Object

g1901_2000.s1911_maximum_alternating_subsequence_sum.Solution

public class Solution
extends Object

1911 - Maximum Alternating Subsequence Sum\. Medium The **alternating sum** of a **0-indexed** array is defined as the **sum** of the elements at **even** indices **minus** the **sum** of the elements at **odd** indices. * For example, the alternating sum of `[4,2,5,3]` is `(4 + 5) - (2 + 3) = 4`. Given an array `nums`, return _the **maximum alternating sum** of any subsequence of_ `nums` _(after **reindexing** the elements of the subsequence)_. A **subsequence** of an array is a new array generated from the original array by deleting some elements (possibly none) without changing the remaining elements' relative order. For example, `[2,7,4]` is a subsequence of `[4,2,3,7,2,1,4]` (the underlined elements), while `[2,4,2]` is not. **Example 1:** **Input:** nums = [4,2,5,3] **Output:** 7 **Explanation:** It is optimal to choose the subsequence [4,2,5] with alternating sum (4 + 5) - 2 = 7. **Example 2:** **Input:** nums = [5,6,7,8] **Output:** 8 **Explanation:** It is optimal to choose the subsequence [8] with alternating sum 8. **Example 3:** **Input:** nums = [6,2,1,2,4,5] **Output:** 10 **Explanation:** It is optimal to choose the subsequence [6,1,5] with alternating sum (6 + 5) - 1 = 10. **Constraints:** * 1 <= nums.length <= 105 * 1 <= nums[i] <= 105

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
long	maxAlternatingSum(int[] nums)

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

maxAlternatingSum

public long maxAlternatingSum(int[] nums)