In the following pseudocode, let $A$ be an array of $n$ positive integers, $x$ be a positive integer number, start be an index, $p$ be a list of integers, and result be a list of lists.

b$)$ Find an upper bound for its t$$ne complexity $(T).$ Hint: You need to write $T(n,x)$ as a recurrence relation and solve it by expanding it$.$

function func $(A,x)$ :

A$.$ sort $()$

result $=[]$

Mystery $($A$,$ x$,0,[],$ result$)$

return result

function Mystery$(A,x,$ start, $p,$ result$)$:

if $x=0$;

result.append $(p)$

return

if $x<0$ :

return

for i from start to $n-1$ :

$,$ result$)$

I got recurrence relation t$($n$,$x$)=$t$($n$-1,$X$-$a$[0])+$t$($n$-2,$x$-$a$[1])+...+$t$(0,$x$-$a$[$n$-1])$ further expand and solve it give me correct time complexity