problem in here N is equal to A given an array's length. Your task is to find the maximum partition-array sum that can be achieved after performing the following operation once. Select some sub-array from the array and set all elements in it to 0. find the maximum sum of the sub-array that can be reached.

Problem

Translate in english: Tests number. Given N length array. You can do choose optional subarray and it turns all elements of the subarray to 0. And asked from you what is maximum sum of array's subarray. test 1 4 -1 4 -1 2

-1 4 [0] 2 -> -1 [4 0 2] -> 6