A $$tracing tree$$ shows the order of the execution for the chain of function calls, to help us better understand how the output is generated and what the memory looks like for each function call. When function A calls function B$,$ the name of function B should be written underneath A$,$ with an indentation. We use an arrow to show A called B $($see the blue arrow below$).$ The return value is also shown next to the arrow that follows the name of the function $($see the red arrows below$)$

We can use the tracing tree to get an understanding of how a recursion works.

In this activity, suppose we call the given method with $($input$,0,4),$ where input is an integer array containing $\{1,2,3,4,5\}.$ Fill in the gaps in the tracing tree that shows the correct order of function call in this recursion.

Background image for dragging markers ontoblank blank blank blank blank blank blank blank blank blank blank blank blank blank blank blank blank