Getting Data from a List. Given the following method

Integer foo$($ List a $)\{$

Integer sum$=$new Integer$(0)$;

for$($int x $=0$; x $<$ a$.$size$()$; x$++)\{$

sum $+=$ a$.$get$($ x $)*$ a$.$get$($ a$.$size$()-$ x $-1)$;

$\}$

return sum;

$\}$

a$.$ What prints out for a call to System.out.println$($foo$($list$))$ if the list contains $\{1,2,3,4\}?$

b$.$ What is the Big$-$O if we call foo$($list$)$ where the list is a LinkedList with N elements

in it$?$ Explain.

c$.$ What is the Big$-$O if we call foo$($list$)$ where the list is an ArrayList with N elements

in it$?$ Explain.