Mode: Add Node
Speed
Add Node mode: click to place nodes | Add Edge mode: click node → click another | Drag nodes to rearrange
Algorithm Stack
Discovered SCCs
Node State
| Node | disc | low | onStack |
|---|
How It Works
Tarjan's algorithm finds all Strongly Connected Components in a directed graph in O(V + E) time.
It uses a single DFS traversal with a stack to track the current path. Each node gets a disc (discovery time) and low (lowest reachable disc via DFS subtree).
When
It uses a single DFS traversal with a stack to track the current path. Each node gets a disc (discovery time) and low (lowest reachable disc via DFS subtree).
When
disc[v] == low[v], node v is the root of an SCC — pop the stack until you reach v.
Legend
Unvisited node
Currently processing (on stack)
Current DFS node
SCC complete
Tree / forward edge
Back edge (cycle!)