Basic graph implementation without reverse arc. More...
#include <graph.h>
Classes | |
| class | OutgoingArcIterator |
| class | OutgoingHeadIterator |
Public Types | |
| typedef NodeIndexType | NodeIndex |
| Typedef so you can use Graph::NodeIndex and Graph::ArcIndex to be generic but also to improve the readability of your code. More... | |
| typedef ArcIndexType | ArcIndex |
Public Member Functions | |
| ListGraph () | |
| ListGraph (NodeIndexType num_nodes, ArcIndexType arc_capacity) | |
| Reserve space for the graph at construction and do not allow it to grow beyond that, see FreezeCapacities(). More... | |
| void | AddNode (NodeIndexType node) |
| If node is not a valid node, sets num_nodes_ to node + 1 so that the given node becomes valid. More... | |
| ArcIndexType | AddArc (NodeIndexType tail, NodeIndexType head) |
| Adds an arc to the graph and returns its current index which will always be num_arcs() - 1. More... | |
| void | Build () |
| Some graph implementations need to be finalized with Build() before they can be used. More... | |
| void | Build (std::vector< ArcIndexType > *permutation) |
| ArcIndexType | OutDegree (NodeIndexType node) const |
| Graph jargon: the "degree" of a node is its number of arcs. More... | |
| BeginEndWrapper< OutgoingArcIterator > | OutgoingArcs (NodeIndexType node) const |
| Allows to iterate over the forward arcs that verify Tail(arc) == node. More... | |
| BeginEndWrapper< OutgoingArcIterator > | OutgoingArcsStartingFrom (NodeIndexType node, ArcIndexType from) const |
| Advanced usage. More... | |
| BeginEndWrapper< OutgoingHeadIterator > | operator[] (NodeIndexType node) const |
| This loops over the heads of the OutgoingArcs(node). More... | |
| NodeIndexType | Tail (ArcIndexType arc) const |
| Returns the tail/head of a valid arc. More... | |
| NodeIndexType | Head (ArcIndexType arc) const |
| void | ReserveNodes (NodeIndexType bound) override |
| Changes the graph capacities. More... | |
| void | ReserveArcs (ArcIndexType bound) override |
| NodeIndexType | num_nodes () const |
| Returns the number of valid nodes in the graph. More... | |
| ArcIndexType | num_arcs () const |
| Returns the number of valid arcs in the graph. More... | |
| IntegerRange< NodeIndex > | AllNodes () const |
| Allows nice range-based for loop: for (const NodeIndex node : graph.AllNodes()) { ... More... | |
| IntegerRange< ArcIndex > | AllForwardArcs () const |
| bool | IsNodeValid (NodeIndexType node) const |
| Returns true if the given node is a valid node of the graph. More... | |
| bool | IsArcValid (ArcIndexType arc) const |
| Returns true if the given arc is a valid arc of the graph. More... | |
| NodeIndexType | node_capacity () const |
| Capacity reserved for future nodes, always >= num_nodes_. More... | |
| ArcIndexType | arc_capacity () const |
| Capacity reserved for future arcs, always >= num_arcs_. More... | |
| void | Reserve (NodeIndexType node_capacity, ArcIndexType arc_capacity) |
| void | FreezeCapacities () |
| FreezeCapacities() makes any future attempt to change the graph capacities crash in DEBUG mode. More... | |
| void | GroupForwardArcsByFunctor (const A &a, B *b) |
| ArcIndexType | max_end_arc_index () const |
Static Public Attributes | |
| static const NodeIndexType | kNilNode |
| Constants that will never be a valid node or arc. More... | |
| static const ArcIndexType | kNilArc |
Protected Member Functions | |
| void | ComputeCumulativeSum (std::vector< ArcIndexType > *v) |
| Functions commented when defined because they are implementation details. More... | |
| void | BuildStartAndForwardHead (SVector< NodeIndexType > *head, std::vector< ArcIndexType > *start, std::vector< ArcIndexType > *permutation) |
| Given the tail of arc #i in (*head)[i] and the head of arc #i in (*head)[~i]. More... | |
Protected Attributes | |
| NodeIndexType | num_nodes_ |
| NodeIndexType | node_capacity_ |
| ArcIndexType | num_arcs_ |
| ArcIndexType | arc_capacity_ |
| bool | const_capacities_ |
Detailed Description
template<typename NodeIndexType = int32, typename ArcIndexType = int32>
class util::ListGraph< NodeIndexType, ArcIndexType >
Basic graph implementation without reverse arc.
This class also serves as a documentation for the generic graph interface (minus the part related to reverse arcs).
This implementation uses a linked list and compared to StaticGraph:
- Is a bit faster to construct (if the arcs are not ordered by tail).
- Does not require calling Build().
- Has slower outgoing arc iteration.
- Uses more memory: ArcIndexType * node_capacity()
- (ArcIndexType + NodeIndexType) * arc_capacity().
- Has an efficient Tail() but need an extra NodeIndexType/arc memory for it.
- Never changes the initial arc index returned by AddArc().
Member Typedef Documentation
◆ ArcIndex
|
inherited |
◆ NodeIndex
|
inherited |
Typedef so you can use Graph::NodeIndex and Graph::ArcIndex to be generic but also to improve the readability of your code.
We also recommend that you define a typedef ... Graph; for readability.
Constructor & Destructor Documentation
◆ ListGraph() [1/2]
|
inline |
◆ ListGraph() [2/2]
|
inline |
Reserve space for the graph at construction and do not allow it to grow beyond that, see FreezeCapacities().
This constructor also makes any nodes in [0, num_nodes) valid.
Member Function Documentation
◆ AddArc()
| ArcIndexType util::ListGraph< NodeIndexType, ArcIndexType >::AddArc | ( | NodeIndexType | tail, |
| NodeIndexType | head | ||
| ) |
Adds an arc to the graph and returns its current index which will always be num_arcs() - 1.
It will also automatically call AddNode(tail) and AddNode(head). It will fail in DEBUG mode if the capacities are fixed and this cause the graph to grow beyond them.
- Note
- Self referencing arcs and duplicate arcs are supported.
◆ AddNode()
| void util::ListGraph< NodeIndexType, ArcIndexType >::AddNode | ( | NodeIndexType | node | ) |
◆ AllForwardArcs()
|
inherited |
◆ AllNodes()
|
inherited |
◆ arc_capacity()
|
inherited |
Capacity reserved for future arcs, always >= num_arcs_.
- Todo:
- (user): Same questions as the ones in node_capacity().
◆ Build() [1/2]
|
inline |
Some graph implementations need to be finalized with Build() before they can be used.
After Build() is called, the arc indices (which had been the return values of previous AddArc() calls) may change: the new index of former arc #i will be stored in permutation[i] if #i is smaller than permutation.size() or will be unchanged otherwise. If you don't care about these, just call the simple no-output version Build().
- Note
- some implementations become immutable after calling Build().
◆ Build() [2/2]
| void util::ListGraph< NodeIndexType, ArcIndexType >::Build | ( | std::vector< ArcIndexType > * | permutation | ) |
◆ BuildStartAndForwardHead()
|
protectedinherited |
Given the tail of arc #i in (*head)[i] and the head of arc #i in (*head)[~i].
- Reorder the arc by increasing tail.
- Put the head of the new arc #i in (*head)[i].
- Put in start[i] the index of the first arc with tail >= i.
- Update "permutation" to reflect the change, unless it is NULL.
Computes the outgoing degree of each nodes and check if we need to permute something or not. Note that the tails are currently stored in the positive range of the SVector head.
Abort early if we do not need the permutation: we only need to put the heads in the positive range.
Computes the forward arc permutation.
- Note
- this temporarily alters the start vector.
Restore in (*start)[i] the index of the first arc with tail >= i.
Permutes the head into their final position in head. We do not need the tails anymore at this point.
◆ ComputeCumulativeSum()
|
protectedinherited |
◆ FreezeCapacities()
|
inherited |
FreezeCapacities() makes any future attempt to change the graph capacities crash in DEBUG mode.
- Todo:
- (user): Only define this in debug mode at the cost of having a lot of ifndef NDEBUG all over the place? remove the function completely ?
◆ GroupForwardArcsByFunctor()
|
inlineinherited |
◆ Head()
| NodeIndexType util::ListGraph< NodeIndexType, ArcIndexType >::Head | ( | ArcIndexType | arc | ) | const |
◆ IsArcValid()
|
inlineinherited |
◆ IsNodeValid()
|
inlineinherited |
◆ max_end_arc_index()
|
inlineinherited |
◆ node_capacity()
|
inherited |
◆ num_arcs()
|
inlineinherited |
◆ num_nodes()
|
inlineinherited |
◆ operator[]()
| BeginEndWrapper< typename ListGraph< NodeIndexType, ArcIndexType >::OutgoingHeadIterator > util::ListGraph< NodeIndexType, ArcIndexType >::operator[] | ( | NodeIndexType | node | ) | const |
◆ OutDegree()
| ArcIndexType util::ListGraph< NodeIndexType, ArcIndexType >::OutDegree | ( | NodeIndexType | node | ) | const |
Graph jargon: the "degree" of a node is its number of arcs.
The out-degree is the number of outgoing arcs. The in-degree is the number of incoming arcs, and is only available for some graph implementations, below.
ListGraph<>::OutDegree() works in O(degree).
◆ OutgoingArcs()
| BeginEndWrapper<OutgoingArcIterator> util::ListGraph< NodeIndexType, ArcIndexType >::OutgoingArcs | ( | NodeIndexType | node | ) | const |
Allows to iterate over the forward arcs that verify Tail(arc) == node.
This is meant to be used as: for (const ArcIndex arc : graph.OutgoingArcs(node)) { ... }
◆ OutgoingArcsStartingFrom()
| BeginEndWrapper<OutgoingArcIterator> util::ListGraph< NodeIndexType, ArcIndexType >::OutgoingArcsStartingFrom | ( | NodeIndexType | node, |
| ArcIndexType | from | ||
| ) | const |
Advanced usage.
Same as OutgoingArcs(), but allows to restart the iteration from an already known outgoing arc of the given node.
◆ Reserve()
|
inlineinherited |
◆ ReserveArcs()
|
overridevirtual |
Reimplemented from util::BaseGraph< NodeIndexType, ArcIndexType, false >.
◆ ReserveNodes()
|
overridevirtual |
Changes the graph capacities.
The functions will fail in debug mode if:
- const_capacities_ is true.
- A valid node does not fall into the new node range.
- A valid arc does not fall into the new arc range. In non-debug mode, const_capacities_ is ignored and nothing will happen if the new capacity value for the arcs or the nodes is too small.
Reimplemented from util::BaseGraph< NodeIndexType, ArcIndexType, false >.
◆ Tail()
| NodeIndexType util::ListGraph< NodeIndexType, ArcIndexType >::Tail | ( | ArcIndexType | arc | ) | const |
Member Data Documentation
◆ arc_capacity_
|
protectedinherited |
◆ const_capacities_
|
protectedinherited |
◆ kNilArc
|
staticinherited |
◆ kNilNode
|
staticinherited |
◆ node_capacity_
|
protectedinherited |
◆ num_arcs_
|
protectedinherited |
◆ num_nodes_
|
protectedinherited |
The documentation for this class was generated from the following file: