Version 5.0 The LEDA User Manual

ool it.eol( ) returns !it.valid( ) which is true if and only if there is
no successor edge left, i.e. if all edges of the edge set
are passed (eol: end of list).
bool it.valid( ) returns true if and only if end of sequence not yet
passed, i.e. if there is an edge in the edge set that was
not yet passed.
leda :: edge it.get edge( ) returns the marked edge or nil if it.valid( ) returns
false.
leda :: node it.get node( ) returns the marked node or nil if it.has node( ) returns
false.
const leda :: graph& it.get graph( )
returns the associated graph.
InAdjIt it.curr adj( ) returns a new adjacency iterator that is associated
with n’ = source(e) and G.first in edge(n’) where G is
the associated graph.
Precondition: it.valid( ) returns true.
InAdjIt& ++it performs one step forward in the list of incoming edges
of the marked node. If there is no successor edge,
it.eol( ) will be true afterwards. This method returns
a reference to it.
Precondition: it.valid( ) returns true.
InAdjIt& −−it performs one step backward in the list of incoming
edges of the marked node. If there is no predecesssor
edge, it.eol( ) will be true afterwards. This method
returns a reference to it.
Precondition: it.valid( ) returns true.
4. Implementation
Creation of an iterator and all methods take constant time.
13.7 Adjacency Iterators ( AdjIt )
1. Definition
a variable it of class AdjIt is an adjacency iterator that marks a node (which is fixed in
contrast to linear node iterators) and iterates over the edges that leave or enter this node.
At first, all outgoing edges will be traversed.
Internally, this iterator creates two instances of OutAdjIt and InAdjIt. The iteration is
a sequenced iteration over both iterators. Note that this only fits for directed graph, for
undirected graph you should use OutAdjIt instead.