LEMON 1.0.7
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This class provides an efficient implementation of the DFS algorithm.
There is also a function-type interface for the DFS algorithm, which is convenient in the simplier cases and it can be used easier.
GR | The type of the digraph the algorithm runs on. The default value is ListDigraph. The value of GR is not used directly by Dfs, it is only passed to DfsDefaultTraits. |
TR | Traits class to set various data types used by the algorithm. The default traits class is DfsDefaultTraits<GR>. See DfsDefaultTraits for the documentation of a Dfs traits class. |
#include <lemon/dfs.h>
Classes | |
struct | SetDistMap |
struct | SetPredMap |
struct | SetProcessedMap |
struct | SetReachedMap |
struct | SetStandardProcessedMap |
Named parameter for setting ProcessedMap type to be Digraph::NodeMap<bool> . More... | |
Public Types | |
typedef TR::Digraph | Digraph |
The type of the digraph the algorithm runs on. | |
typedef TR::PredMap | PredMap |
The type of the map that stores the predecessor arcs of the DFS paths. | |
typedef TR::DistMap | DistMap |
The type of the map that stores the distances of the nodes. | |
typedef TR::ReachedMap | ReachedMap |
The type of the map that indicates which nodes are reached. | |
typedef TR::ProcessedMap | ProcessedMap |
The type of the map that indicates which nodes are processed. | |
typedef PredMapPath< Digraph, PredMap > | Path |
The type of the paths. | |
typedef TR | Traits |
The traits class. | |
Public Member Functions | |
Dfs (const Digraph &g) | |
Constructor. | |
~Dfs () | |
Destructor. | |
Dfs & | predMap (PredMap &m) |
Sets the map that stores the predecessor arcs. | |
Dfs & | reachedMap (ReachedMap &m) |
Sets the map that indicates which nodes are reached. | |
Dfs & | processedMap (ProcessedMap &m) |
Sets the map that indicates which nodes are processed. | |
Dfs & | distMap (DistMap &m) |
Sets the map that stores the distances of the nodes. | |
Execution control | |
The simplest way to execute the algorithm is to use one of the member functions called run(). | |
void | init () |
void | addSource (Node s) |
Adds a new source node. | |
Arc | processNextArc () |
Processes the next arc. | |
OutArcIt | nextArc () const |
Next arc to be processed. | |
bool | emptyQueue () const |
Returns false if there are nodes to be processed. | |
int | queueSize () const |
Returns the number of the nodes to be processed. | |
void | start () |
Executes the algorithm. | |
void | start (Node t) |
Executes the algorithm until the given target node is reached. | |
template<class ArcBoolMap > | |
Arc | start (const ArcBoolMap &am) |
Executes the algorithm until a condition is met. | |
void | run (Node s) |
Runs the algorithm from the given source node. | |
bool | run (Node s, Node t) |
Finds the DFS path between s and t . | |
void | run () |
Runs the algorithm to visit all nodes in the digraph. | |
Query Functions | |
Path | path (Node t) const |
The DFS path to a node. | |
int | dist (Node v) const |
The distance of a node from the root. | |
Arc | predArc (Node v) const |
Returns the 'previous arc' of the DFS tree for a node. | |
Node | predNode (Node v) const |
Returns the 'previous node' of the DFS tree. | |
const DistMap & | distMap () const |
Returns a const reference to the node map that stores the distances of the nodes. | |
const PredMap & | predMap () const |
Returns a const reference to the node map that stores the predecessor arcs. | |
bool | reached (Node v) const |
Checks if a node is reachable from the root(s). |
Sets the map that stores the predecessor arcs. If you don't use this function before calling run(), it will allocate one. The destructor deallocates this automatically allocated map, of course.
(*this)
Dfs& reachedMap | ( | ReachedMap & | m | ) | [inline] |
Sets the map that indicates which nodes are reached. If you don't use this function before calling run(), it will allocate one. The destructor deallocates this automatically allocated map, of course.
(*this)
Dfs& processedMap | ( | ProcessedMap & | m | ) | [inline] |
Sets the map that indicates which nodes are processed. If you don't use this function before calling run(), it will allocate one. The destructor deallocates this automatically allocated map, of course.
(*this)
Sets the map that stores the distances of the nodes calculated by the algorithm. If you don't use this function before calling run(), it will allocate one. The destructor deallocates this automatically allocated map, of course.
(*this)
void init | ( | ) | [inline] |
Initializes the internal data structures.
void addSource | ( | Node | s | ) | [inline] |
Adds a new source node to the set of nodes to be processed.
Arc processNextArc | ( | ) | [inline] |
Processes the next arc.
OutArcIt nextArc | ( | ) | const [inline] |
Next arc to be processed.
INVALID
if the stack is empty. bool emptyQueue | ( | ) | const [inline] |
Returns false
if there are nodes to be processed in the queue (stack).
int queueSize | ( | ) | const [inline] |
Returns the number of the nodes to be processed in the queue (stack).
void start | ( | ) | [inline] |
Executes the algorithm.
This method runs the DFS algorithm from the root node in order to compute the DFS path to each node.
The algorithm computes
d.start()
is just a shortcut of the following code. while ( !d.emptyQueue() ) {
d.processNextArc();
}
void start | ( | Node | t | ) | [inline] |
Executes the algorithm until the given target node is reached.
This method runs the DFS algorithm from the root node in order to compute the DFS path to t
.
The algorithm computes
t
,t
from the root in the DFS tree.Arc start | ( | const ArcBoolMap & | am | ) | [inline] |
Executes the algorithm until a condition is met.
This method runs the DFS algorithm from the root node until an arc a
with am[a]
true is found.
am | A bool (or convertible) arc map. The algorithm will stop when it reaches an arc a with am[a] true. |
a
with am[a]
true or INVALID
if no such arc was found.void run | ( | Node | s | ) | [inline] |
This method runs the DFS algorithm from node s
in order to compute the DFS path to each node.
The algorithm computes
d.run(s)
is just a shortcut of the following code. d.init(); d.addSource(s); d.start();
bool run | ( | Node | s, |
Node | t | ||
) | [inline] |
This method runs the DFS algorithm from node s
in order to compute the DFS path to node t
(it stops searching when t
is processed)
true
if t
is reachable form s
.d.run(s,t)
is just a shortcut of the following code. d.init(); d.addSource(s); d.start(t);
void run | ( | ) | [inline] |
This method runs the DFS algorithm in order to compute the DFS path to each node.
The algorithm computes
d.run()
is just a shortcut of the following code. d.init(); for (NodeIt n(digraph); n != INVALID; ++n) { if (!d.reached(n)) { d.addSource(n); d.start(); } }
Path path | ( | Node | t | ) | const [inline] |
int dist | ( | Node | v | ) | const [inline] |
Arc predArc | ( | Node | v | ) | const [inline] |
This function returns the 'previous arc' of the DFS tree for the node v
, i.e. it returns the last arc of a DFS path from the root to v
. It is INVALID
if v
is not reachable from the root(s) or if v
is a root.
The DFS tree used here is equal to the DFS tree used in predNode().
Node predNode | ( | Node | v | ) | const [inline] |
This function returns the 'previous node' of the DFS tree for the node v
, i.e. it returns the last but one node from a DFS path from the root to v
. It is INVALID
if v
is not reachable from the root(s) or if v
is a root.
The DFS tree used here is equal to the DFS tree used in predArc().
const DistMap& distMap | ( | ) | const [inline] |
const PredMap& predMap | ( | ) | const [inline] |
bool reached | ( | Node | v | ) | const [inline] |