I was WA#2 and now I get Ac,
because: Graph can be not connected

I got WA#2 too,
but I thought that the graph is supposed to be not connected.

Can help me identify my errors , here's my solution :
- I reverse all the edges
- DFS from the vertex without any other vertex pointing to
- Count the depth, if depth = number of vertex -> output in reverse order

3Q,i made the same mistake,and i now get AC