Find a topological ordering by using a queue data structure in the linear time

$($i$.$e$.$ O $(|$V$|+|$E$|))$ algorithm discussed in class. Make sure to examine the vertices

adjacent to a node in the order they appear on the corresponding singly linked lists.

Note that since you need to use a queue data structure, you should process the

vertices with in$-$degree zero in a FIFO $($First$-$In First$-$Out$)$ order. $(15$ pts$.)$