Consider the following directed graph $G$ given by adjacency lists $($first column indicates

the vertex, the second column lists its outgoing edges as a list$)$:

Perform Depth$-$First Search on this graph starting from vertex $0.$ Indicate the stack

after each addition$/$removal$,$ the order in which the vertices are marked $($start every

new DFS from the first unmarked vertex$).$ Find a topological order of the vertices if

there is one.