MathWorksOA #17
Maximum Even Sum Subsequence
估计中等评测数据准备中，可先阅读题面
Given a array of n positive and negative integers, find the subsequence with the maximum even sum and display that even sum.
Constraints
N/A
Example 1
Input:
arr = [-2, 2, -3, 1, 3]
Output:
6
Explanation: The longest subsequence with even sum is 2, 1 and 3.
Example 2
Input:
arr = [-2, 2, -3, 4, 5]
Output:
8
Explanation: The longest subsequence with even sum is 2, -3, 4 and 5.