$[3$ pts$]$ What function is computed by the function Mystery $(n)$ below? Express your

answer as a summation and then give its closed form.

Mystery $(n)\{$

Sum $=0$;

for $(i=1$;$in$;$i+t)$

for $(j=1$;$ji$;$j++)$

sum$++$;

return sum;

$\}$

$[2$ pts$]$ For the following Bubblesort algorithm, how many times would the inner for loop

iterate $($give the closed form$)?$ What is the worst$-$case running time of Bubblesort?

BUBBLESORT$($A$)$

$1$ for $i=1$ to A$.$length$-1$

$2$ for $j=$ A$.$ length downto $i+1//$downto means decrease by $1$

$4,$ if $A[J]A[J-1]A[J]$

exchange $A[J]$ with $A[J-1]$