Strong Orientation — Robbins' Theorem

Watch a DFS orient every undirected edge: tree edges go down, back edges go up. If a bridge exists, no strong orientation is possible.

Press Step or Run to begin the DFS orientation.
Node colors: unvisited   active (on DFS stack)   visited. Each node shows disc/low once computed.

Legend

Tree edge — oriented down (parent → child)
Back edge — oriented up (descendant → ancestor)
Bridge — no strong orientation
Active vertex (current DFS frame)
Finished vertex

Trace Log

Edge Orientations

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