Duestion $4$: $[4$ marks$]$ Consider the following buggy implementation, answer the following questions:

OLUloderTs$*p=$ head;

if nultptr$)$

return;

while $($p$->$val $v)$

$p=p$ next;

if nullptr $6.pta1l\{$

tail $$ next $=p$;

p $$ prev $$ next $=$ p$-$rnext;

$p$ next $$ prev $=p$ prev;

$p$ prev $=$ tail;

$p$ next $=$ nullptr;

tall$=$ tall $$ next

$\}$

a$.$ Assuming $v=6,$ redraw the following list after executing the above code.

b$.$ Explain what the code is intended to do$.$ Provide a brief description of the purpose of the code, not a line$-$by$-$line explanation.

c$.$ Give an example of a linked list on which this code wouldn't work correctly, and explain what the error is$.$

d$.$ Assuming the list is of size $n,$ what is the worat case running time of this code?