StaticDigraph Class Reference

Detailed Description

StaticDigraph is a highly efficient digraph implementation, but it is fully static. It stores only two int values for each node and only four int values for each arc. Moreover it provides faster item iteration than ListDigraph and SmartDigraph, especially using OutArcIt iterators, since its arcs are stored in an appropriate order. However it only provides build() and clear() functions and does not support any other modification of the digraph.

Since this digraph structure is completely static, its nodes and arcs can be indexed with integers from the ranges [0..nodeNum()-1] and [0..arcNum()-1], respectively. The index of an item is the same as its ID, it can be obtained using the corresponding index() or id() function. A node or arc with a certain index can be obtained using node() or arc().

This type fully conforms to the Digraph concept. Most of its member functions and nested classes are documented only in the concept class.

This class provides constant time counting for nodes and arcs.

See Also

concepts::Digraph

#include <lemon/static_graph.h>

Inherits DigraphExtender< Base >.

Public Member Functions
	StaticDigraph ()
	Constructor.
int	nodeNum () const
	Number of nodes.
int	arcNum () const
	Number of arcs.
template<typename Digraph , typename NodeRefMap , typename ArcRefMap >
void	build (const Digraph &digraph, NodeRefMap &nodeRef, ArcRefMap &arcRef)
	Build the digraph copying another digraph.
template<typename ArcListIterator >
void	build (int n, ArcListIterator begin, ArcListIterator end)
	Build the digraph from an arc list.
void	clear ()
	Clear the digraph.

Static Public Member Functions
static Node	node (int ix)
	The node with the given index.
static Arc	arc (int ix)
	The arc with the given index.
static int	index (Node node)
	The index of the given node.
static int	index (Arc arc)
	The index of the given arc.

Constructor & Destructor Documentation

StaticDigraph ( )

inline

Default constructor.

Member Function Documentation

static Node node ( int  ix )

inlinestatic

This function returns the node with the given index.

See Also

index()

static Arc arc ( int  ix )

inlinestatic

This function returns the arc with the given index.

See Also

index()

static int index ( Node  node )

inlinestatic

This function returns the index of the the given node.

See Also

node()

static int index ( Arc  arc )

inlinestatic

This function returns the index of the the given arc.

See Also

arc()

int nodeNum ( ) const

inline

This function returns the number of nodes.

int arcNum ( ) const

inline

This function returns the number of arcs.

void build ( const Digraph &  digraph, NodeRefMap &  nodeRef, ArcRefMap &  arcRef  )

inline

This function builds the digraph copying another digraph of any kind. It can be called more than once, but in such case, the whole structure and all maps will be cleared and rebuilt.

This method also makes possible to copy a digraph to a StaticDigraph structure using DigraphCopy.

Parameters

digraph	An existing digraph to be copied.
nodeRef	The node references will be copied into this map. Its key type must be Digraph::Node and its value type must be StaticDigraph::Node. It must conform to the ReadWriteMap concept.
arcRef	The arc references will be copied into this map. Its key type must be Digraph::Arc and its value type must be StaticDigraph::Arc. It must conform to the WriteMap concept.

Note

If you do not need the arc references, then you could use NullMap for the last parameter. However the node references are required by the function itself, thus they must be readable from the map.

void build ( int  n, ArcListIterator  begin, ArcListIterator  end  )

inline

This function builds the digraph from the given arc list. It can be called more than once, but in such case, the whole structure and all maps will be cleared and rebuilt.

The list of the arcs must be given in the range [begin, end) specified by STL compatible itartors whose value_type must be std::pair<int,int>. Each arc must be specified by a pair of integer indices from the range [0..n-1]. The pairs must be in a non-decreasing order with respect to their first values. If the k-th pair in the list is (i,j), then arc(k-1) will connect node(i) to node(j).

Parameters

n	The number of nodes.
begin	An iterator pointing to the beginning of the arc list.
end	An iterator pointing to the end of the arc list.

For example, a simple digraph can be constructed like this.

std::vector<std::pair<int,int> > arcs;
arcs.push_back(std::make_pair(0,1));
arcs.push_back(std::make_pair(0,2));
arcs.push_back(std::make_pair(1,3));
arcs.push_back(std::make_pair(1,2));
arcs.push_back(std::make_pair(3,0));
StaticDigraph gr;
gr.build(4, arcs.begin(), arcs.end());

void clear ( )

inline

This function erases all nodes and arcs from the digraph.