Initialization

This page contains information about initialising the ActionDigraph class.

inline void libsemigroups::ActionDigraph::add_edge(node_type i, node_type j, label_type lbl)

Add an edge from one node to another with a given label.

If i and j are nodes in this, and lbl is in the range [0, out_degree()), then this function adds an edge from i to j labelled lbl.

Complexity

Constant.

Parameters:

  • i – the source node

  • j – the range node

  • lbl – the label of the edge from i to j

Throws:

LibsemigroupsException – if i, j, or lbl is not valid. If an exception is thrown, this is guaranteed not to be modified (strong exception guarantee).

Returns:

(None)

inline void libsemigroups::ActionDigraph::add_edge_nc(node_type i, node_type j, label_type lbl)

Add an edge from one node to another with a given label.

Complexity

Constant.

Warning

No checks whatsoever on the validity of the arguments are performed.

Parameters:

  • i – the source node

  • j – the range node

  • lbl – the label of the edge from i to j

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

Returns:

(None)

inline void libsemigroups::ActionDigraph::add_nodes(size_t nr)

Adds a number of new nodes.

Complexity

Linear in number_of_nodes() + nr.

Iterator validity

This function modifies the object defined by this, any iterators, pointers or references pointing into this may be invalidated by a call to this function.

Parameters:

nr – the number of nodes to add.

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException. If an exception is thrown, this is guaranteed not to be modified (strong exception guarantee).

Returns:

(None)

inline void libsemigroups::ActionDigraph::add_to_out_degree(size_t nr)

Adds to the out-degree.

Complexity

\(O(mn)\) where m is the number of nodes, and n is the new out degree of the digraph.

Iterator validity

This function modifies the object defined by this, any iterators, pointers or references pointing into this may be invalidated by a call to this function.

Parameters:

nr – the number of new out-edges for every node.

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException. If an exception is thrown, this is guaranteed not to be modified (strong exception guarantee).

Returns:

(None)

void libsemigroups::ActionDigraph::init(T m, T n)

Re-initialize the digraph to have m nodes and out-degree n

This functions puts a digraph into the state that it would have been in if it had just been newly constructed with the same parameters m and n.

Complexity

\(O(mn)\) where m is the number of nodes, and n is the out-degree of the digraph.

Parameters:

  • m – the number of nodes in the digraph.

  • n – the out-degree of every node.

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

inline void libsemigroups::ActionDigraph::remove_edge_nc(node_type i, label_type lbl)

Remove an edge from a node with a given label.

Complexity

Constant.

Warning

No checks whatsoever on the validity of the arguments are performed.

Parameters:

  • i – the source node

  • lbl – the label of the edge from i

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

Returns:

(None)

inline void libsemigroups::ActionDigraph::reserve(T m, T n) const

Ensures that the digraph has capacity for a given number of nodes, and out-degree.

Complexity

\(O(mn)\) where m is the number of nodes and n is the out-degree.

Iterator validity

This function modifies the object defined by this, any iterators, pointers or references pointing into this may be invalidated by a call to this function.

Note

Does not modify number_of_nodes() or out_degree().

Parameters:

  • m – the number of nodes

  • n – the out-degree

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

Returns:

(None)

inline void libsemigroups::ActionDigraph::restrict(size_t n)

Restrict the digraph to its first n nodes.

Warning

This function performs no checks whatsoever and will result in a corrupted digraph if there are any edges from the nodes \(0, \ldots, n - 1\) to nodes larger than \(n - 1\).

Parameters:

n – the number of nodes

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

Returns:

(None)

inline void libsemigroups::ActionDigraph::swap_edges_nc(node_type u, node_type v, label_type a)

Swaps the edge with specified label from one node with another.

This function swaps the target of the edge from the node u labelled a with the target of the edge from the node v labelled a.

Complexity

Constant

Warning

No checks whatsoever on the validity of the arguments are performed.

Parameters:

  • u – the first node

  • v – the second node

  • a – the label

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

Returns:

(None)