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 v. 2022.02 (Dogwood)
 

ogdf::MinSteinerTreeRZLoss< T > Class Template Reference

This class implements the loss-contracting (1.55+epsilon)-approximation algorithm for the Steiner tree problem by Robins and Zelikovsky. More...

#include <ogdf/graphalg/MinSteinerTreeRZLoss.h>

+ Inheritance diagram for ogdf::MinSteinerTreeRZLoss< T >:

Classes

class  Main
 

Public Member Functions

 MinSteinerTreeRZLoss ()
 
 MinSteinerTreeRZLoss (int v)
 
virtual ~MinSteinerTreeRZLoss ()
 
long numberOfComponentLookUps ()
 Returns the number of components lookups during execution time. More...
 
long numberOfContractedComponents ()
 Returns the number of contracted components. More...
 
long numberOfGeneratedComponents ()
 Returns the number of generated components. More...
 
void setMaxComponentSize (int k)
 Sets the maximal number of terminals in a full component. More...
 
- Public Member Functions inherited from ogdf::MinSteinerTreeModule< T >
virtual ~MinSteinerTreeModule ()
 Do nothing on destruction. More...
 
virtual T call (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, EdgeWeightedGraphCopy< T > *&finalSteinerTree)
 Calls the Steiner tree algorithm for nontrivial cases but handles trivial cases directly. More...
 

Protected Member Functions

virtual T computeSteinerTree (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, EdgeWeightedGraphCopy< T > *&finalSteinerTree) override
 Builds a minimum Steiner tree given a weighted graph and a list of terminals. More...
 

Private Attributes

std::unique_ptr< Mainm_alg
 
int m_restricted
 

Additional Inherited Members

- Static Public Member Functions inherited from ogdf::MinSteinerTreeModule< T >
static void getNonterminals (ArrayBuffer< node > &nonterminals, const EdgeWeightedGraph< T > &G, const NodeArray< bool > &isTerminal)
 Generates a list (as ArrayBuffer<node>) of all nonterminals. More...
 
static void getTerminals (List< node > &terminals, const EdgeWeightedGraph< T > &G, const NodeArray< bool > &isTerminal)
 Generates a list (as List<node>) of all terminals. More...
 
static bool isQuasiBipartite (const EdgeWeightedGraph< T > &G, const NodeArray< bool > &isTerminal)
 Checks in O(n + m) time if a given Steiner tree problem instance is quasi-bipartite. More...
 
static bool isSteinerTree (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, const EdgeWeightedGraphCopy< T > &steinerTree)
 Checks in O(n) time if a given tree is acually a Steiner Tree. More...
 
static void sortTerminals (List< node > &terminals)
 Sort terminals by index. More...
 
static T pruneAllDanglingSteinerPaths (EdgeWeightedGraphCopy< T > &steinerTree, const NodeArray< bool > &isTerminal)
 Prunes nonterminal leaves and their paths to terminal or branching nodes. More...
 
static T pruneDanglingSteinerPathFrom (EdgeWeightedGraphCopy< T > &steinerTree, const NodeArray< bool > &isTerminal, node start)
 Prunes the dangling Steiner path beginning at a given nonterminal leaf only. More...
 
static T pruneDanglingSteinerPathsFrom (EdgeWeightedGraphCopy< T > &steinerTree, const NodeArray< bool > &isTerminal, const List< node > &start)
 Prunes dangling Steiner paths beginning at given nonterminal leaves only. More...
 
static T removeCyclesFrom (EdgeWeightedGraphCopy< T > &steinerTree, const NodeArray< bool > &isTerminal)
 Remove remaining cycles from a Steiner "almost" tree. More...
 
static void singleSourceShortestPathsPreferringTerminals (const EdgeWeightedGraph< T > &G, node source, const NodeArray< bool > &isTerminal, NodeArray< T > &distance, NodeArray< edge > &pred)
 Modified single-source-shortest-paths (Dijkstra) with heuristic to prefer paths over terminals. More...
 
static void singleSourceShortestPathsStandard (const EdgeWeightedGraph< T > &G, node source, const NodeArray< bool > &, NodeArray< T > &distance, NodeArray< edge > &pred)
 Standard single-source-shortest-paths algoritm (Dijkstra) More...
 
static void singleSourceShortestPaths (const EdgeWeightedGraph< T > &G, node source, const NodeArray< bool > &isTerminal, NodeArray< T > &distance, NodeArray< edge > &pred)
 The default single-source-shortest-paths algorithm. More...
 
static void allTerminalShortestPathsStandard (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred)
 Runs singleSourceShortestPathsStandard from all terminals. More...
 
static void allTerminalShortestPathsPreferringTerminals (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred)
 Runs singleSourceShortestPathsPreferringTerminals from all terminals. More...
 
static void allTerminalShortestPaths (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred, std::function< void(const EdgeWeightedGraph< T > &, node, const NodeArray< bool > &, NodeArray< T > &, NodeArray< edge > &)> ssspFunc=singleSourceShortestPaths)
 Runs a given (or the default) single-source-shortest-paths function from all terminals. More...
 
static void allNodeShortestPathsStandard (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred)
 Runs singleSourceShortestPathsStandard from all nodes. More...
 
static void allNodeShortestPathsPreferringTerminals (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred)
 Runs singleSourceShortestPathsPreferringTerminals from all nodes. More...
 
static void allNodeShortestPaths (const EdgeWeightedGraph< T > &G, const List< node > &terminals, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred, std::function< void(const EdgeWeightedGraph< T > &, node, const NodeArray< bool > &, NodeArray< T > &, NodeArray< edge > &)> ssspFunc=singleSourceShortestPaths)
 Runs a given (or the default) single-source-shortest-paths function from all nodes. More...
 
static void allPairShortestPathsPreferringTerminals (const EdgeWeightedGraph< T > &G, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred)
 Modified all-pair-shortest-paths algorithm (Floyd-Warshall) with heuristic to prefer paths over terminals. More...
 
static void allPairShortestPathsStandard (const EdgeWeightedGraph< T > &G, const NodeArray< bool > &, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred)
 Standard all-pair-shortest-paths algorithm (Floyd-Warshall) More...
 
static void allPairShortestPaths (const EdgeWeightedGraph< T > &G, const NodeArray< bool > &isTerminal, NodeArray< NodeArray< T >> &distance, NodeArray< NodeArray< edge >> &pred)
 The default all-pair-shortest-paths algorithm. More...
 
static void drawSVG (const EdgeWeightedGraph< T > &G, const NodeArray< bool > &isTerminal, const EdgeWeightedGraphCopy< T > &steinerTree, const char *filename)
 Writes an SVG file of a minimum Steiner tree in the original graph. More...
 
static void drawSVG (const EdgeWeightedGraph< T > &G, const NodeArray< bool > &isTerminal, const char *filename)
 Writes an SVG file of the instance graph. More...
 
static void drawSteinerTreeSVG (const EdgeWeightedGraphCopy< T > &steinerTree, const NodeArray< bool > &isTerminal, const char *filename)
 Writes a SVG that shows only the given Steiner tree. More...
 

Detailed Description

template<typename T>
class ogdf::MinSteinerTreeRZLoss< T >

This class implements the loss-contracting (1.55+epsilon)-approximation algorithm for the Steiner tree problem by Robins and Zelikovsky.

This implementation is based on:

(G. Robins, A. Zelikovsky, Improved Steiner Tree Approximation in Graphs, SODA 2000, pages 770-779, SIAM, 2000)

Definition at line 61 of file MinSteinerTreeRZLoss.h.

Constructor & Destructor Documentation

◆ MinSteinerTreeRZLoss() [1/2]

template<typename T >
ogdf::MinSteinerTreeRZLoss< T >::MinSteinerTreeRZLoss ( )
inline

Definition at line 68 of file MinSteinerTreeRZLoss.h.

◆ MinSteinerTreeRZLoss() [2/2]

template<typename T >
ogdf::MinSteinerTreeRZLoss< T >::MinSteinerTreeRZLoss ( int  v)
inline

Definition at line 73 of file MinSteinerTreeRZLoss.h.

◆ ~MinSteinerTreeRZLoss()

template<typename T >
virtual ogdf::MinSteinerTreeRZLoss< T >::~MinSteinerTreeRZLoss ( )
inlinevirtual

Definition at line 78 of file MinSteinerTreeRZLoss.h.

Member Function Documentation

◆ computeSteinerTree()

template<typename T >
virtual T ogdf::MinSteinerTreeRZLoss< T >::computeSteinerTree ( const EdgeWeightedGraph< T > &  G,
const List< node > &  terminals,
const NodeArray< bool > &  isTerminal,
EdgeWeightedGraphCopy< T > *&  finalSteinerTree 
)
inlineoverrideprotectedvirtual

Builds a minimum Steiner tree given a weighted graph and a list of terminals.

See also
MinSteinerTreeModule::call
Parameters
GThe weighted input graph
terminalsThe list of terminal nodes
isTerminalA bool array of terminals
finalSteinerTreeThe final Steiner tree
Returns
The objective value (sum of edge costs) of the final Steiner tree

Implements ogdf::MinSteinerTreeModule< T >.

Definition at line 122 of file MinSteinerTreeRZLoss.h.

◆ numberOfComponentLookUps()

template<typename T >
long ogdf::MinSteinerTreeRZLoss< T >::numberOfComponentLookUps ( )
inline

Returns the number of components lookups during execution time.

Definition at line 106 of file MinSteinerTreeRZLoss.h.

◆ numberOfContractedComponents()

template<typename T >
long ogdf::MinSteinerTreeRZLoss< T >::numberOfContractedComponents ( )
inline

Returns the number of contracted components.

Definition at line 98 of file MinSteinerTreeRZLoss.h.

◆ numberOfGeneratedComponents()

template<typename T >
long ogdf::MinSteinerTreeRZLoss< T >::numberOfGeneratedComponents ( )
inline

Returns the number of generated components.

Definition at line 90 of file MinSteinerTreeRZLoss.h.

◆ setMaxComponentSize()

template<typename T >
void ogdf::MinSteinerTreeRZLoss< T >::setMaxComponentSize ( int  k)
inline

Sets the maximal number of terminals in a full component.

Parameters
kthe maximal number of terminals in a full component

Definition at line 84 of file MinSteinerTreeRZLoss.h.

Member Data Documentation

◆ m_alg

template<typename T >
std::unique_ptr<Main> ogdf::MinSteinerTreeRZLoss< T >::m_alg
private

Definition at line 64 of file MinSteinerTreeRZLoss.h.

◆ m_restricted

template<typename T >
int ogdf::MinSteinerTreeRZLoss< T >::m_restricted
private

Definition at line 62 of file MinSteinerTreeRZLoss.h.


The documentation for this class was generated from the following file: