You are given an array of n elements and a sum value, you have to calculate the total number of ways to calculate the given sum using the elements of the array by using only addition(+) and subtraction operator(-).

Value of n should lie between [1,15]

array => [-1, 9, 8, -3, 4] value sum => 5

Output -: 8

I have applied Recursion and Memo also but I want a space Optimization Approach for this Question. Please Explain the Working and Time Complexity of this Code and share the Code snippet.