Version 5.0 The LEDA User Manual

3. Operations
void fc.init(const leda :: graph& G)
associates fc with G.
void fc.init(const leda :: graph& G, const leda :: edge& e)
void fc.update(leda :: edge e)
associates fc with G and marks it with e.
Precondition: e is an edge of G.
fc marks e afterwards.
void fc.make invalid( ) makes fc invalid, i.e. fc.valid( ) will be false afterwards
and fc marks no edge.
FaceCirc&
bool
fc = const FaceCirc& fc2
fc == const FaceCirc& fc2
assigns fc2 to fc. This method returns a reference to
fc.
returns true if and only if fc and fc2 are equal, i.e. if
the marked edges are equal.
bool fc.has edge( ) returns true if and only if fc marks an edge.
bool fc.eol( ) returns !fc.valid( ).
bool fc.valid( ) returns true if and only if the circulator is marked
with an edge.
leda :: edge fc.get edge( ) returns the marked edge or nil if fc.valid( ) returns
false.
const leda :: graph& fc.get graph( ) returns the associated graph.
FaceCirc& ++fc redirects the circulator to the cyclic adjacency predecessor
of reversal(e), where e is the marked edge. This
method returns a reference to fc.
Precondition: fc.valid( ) returns true.
FaceCirc& −−fc redirects the circulator to the cyclic adjacency successor
of e, where e is the marked edge. This method
returns a reference to fc.
Precondition: fc.valid( ) returns true.
4. Implementation
Creation of a circulator and all methods take constant time.