GetTreeRootNId¶
- GetTreeRootNId(Graph)¶
If Graph is a tree, the function returns the root id of the tree. Otherwise, it returns -1.
Parameters:
- Graph: directed graph (input)
A Snap.py directed graph or a network
Return value:
- int
If Graph is a tree, the node id of the root. Otherwise, -1 is returned.
The following example shows how to get the root node id in TNGraph and TNEANet:
import snap
Graph = snap.GenTree(snap.PNGraph, 3, 3)
root_id = snap.GetTreeRootNId(Graph)
print "The graph has a root id: %d" % root_id
Network = snap.GenTree(snap.PNEANet, 3, 3)
root_id = snap.GetTreeRootNId(Network)
print "The graph has a root id: %d" % root_id