Get Minimum Operations

Problem Overview

• Find the minimum number of operations to turn all elements of arr into NULL.
• At step i: decrement any arr element by 1, or if change[i]>0 and arr[change[i]]==0, set that index to NULL; 1-based; return -1 if impossible.
• Inputs: change of size n and arr of size m; output: the minimum operation count.
• Array cleanup/resource deallocation context; from Rubrik interviews, a coding interview problem and interview question.