GridGraph Class Reference

Detailed Description

This class implements a special graph type. The nodes of the graph can be indexed by two integer (i,j) value where i is in the [0..width()-1] range and j is in the [0..height()-1] range. Two nodes are connected in the graph if the indexes differ exactly on one position and exactly one is the difference. The nodes of the graph can be indexed by position with the operator()() function. The positions of the nodes can be get with pos(), col() and row() members. The outgoing arcs can be retrieved with the right(), up(), left() and down() functions, where the bottom-left corner is the origin.

A short example about the basic usage:

GridGraph graph(rows, cols);
GridGraph::NodeMap<int> val(graph);
for (int i = 0; i < graph.width(); ++i) {
  for (int j = 0; j < graph.height(); ++j) {
    val[graph(i, j)] = i + j;
  }
}

This graph type fully conforms to the Graph concept.

#include <lemon/grid_graph.h>

Inherits GraphExtender< Base >.

Classes
class	ColMap
class	IndexMap
class	RowMap

Public Member Functions
	GridGraph (int width, int height)
	Constructor.
void	resize (int width, int height)
	Resize the graph.
Node	operator() (int i, int j) const
	The node on the given position.
int	col (Node n) const
int	row (Node n) const
dim2::Point< int >	pos (Node n) const
	Gives back the position of the node.
int	width () const
int	height () const
Arc	right (Node n) const
	Gives back the arc goes right from the node.
Arc	left (Node n) const
	Gives back the arc goes left from the node.
Arc	up (Node n) const
	Gives back the arc goes up from the node.
Arc	down (Node n) const
	Gives back the arc goes down from the node.
IndexMap	indexMap () const
	Index map of the grid graph.
RowMap	rowMap () const
	Row map of the grid graph.
ColMap	colMap () const
	Column map of the grid graph.

Constructor & Destructor Documentation

GridGraph ( int  width, int  height  )

inline

Construct a grid graph with given size.

Member Function Documentation

void resize ( int  width, int  height  )

inline

Resize the graph. The function will fully destroy and rebuild the graph. This cause that the maps of the graph will reallocated automatically and the previous values will be lost.

Node operator() ( int  i, int  j  ) const

inline

Gives back the node on the given position.

int col ( Node  n ) const

inline

Gives back the column index of the node.

int row ( Node  n ) const

inline

Gives back the row index of the node.

dim2::Point<int> pos ( Node  n ) const

inline

Gives back the position of the node, ie. the (col,row) pair.

int width ( ) const

inline

Gives back the number of the columns.

int height ( ) const

inline

Gives back the number of the rows.

Arc right ( Node  n ) const

inline

Gives back the arc goes right from the node. If there is not outgoing arc then it gives back INVALID.

Arc left ( Node  n ) const

inline

Gives back the arc goes left from the node. If there is not outgoing arc then it gives back INVALID.

Arc up ( Node  n ) const

inline

Gives back the arc goes up from the node. If there is not outgoing arc then it gives back INVALID.

Arc down ( Node  n ) const

inline

Gives back the arc goes down from the node. If there is not outgoing arc then it gives back INVALID.

IndexMap indexMap ( ) const

inline

Just returns an IndexMap for the grid graph.

RowMap rowMap ( ) const

inline

Just returns a RowMap for the grid graph.

ColMap colMap ( ) const

inline

Just returns a ColMap for the grid graph.