Critical Connections - Edge Cases

$1.$ Single edge: $n=2$, connections $[[0,1]]$.

The edge is a bridge. Output: $[[0,1]]$.

$2.$ Complete cycle: $n=3$, connections $[[0,1],[1,2],[2,0]]$.

No bridges. Output: $[]$.

$3.$ Star graph: $n=4$, connections $[[0,1],[0,2],[0,3]]$.

All edges are bridges because each leaf has only one connection. Output: all edges.

$4.$ Disconnected graph: problem guarantees connected, but if not, run DFS from each component.