How to approach the problem

#1

I am able to apply the kadane’s algorithm in normal array but i cannot understand the wrapping method of applying the kadanes? Please help me understanding this approach.

#2

we know that kadane algo is used to find max subarray sum. What is we change the sign of elements in array(make positive element negative and negative element positive) then if we apply kadane algo in this array then it will give the min subarray sum. Try to solve this problem by using this approach.