Definition
a variable it of class AdjIt is an adjacency iterator that marks a node (which is fixed in contrast to linear node iterators) and iterates over the edges that leave or enter this node. At first, all outgoing edges will be traversed.
Internally, this iterator creates two instances of OutAdjIt and InAdjIt. The iteration is a sequenced iteration over both iterators. Note that this only fits for directed graph, for undirected graph you should use OutAdjIt instead.
#include < LEDA/graph/graph_iterator.h >
Creation
AdjIt | it | introduces a variable it of this class associated with no graph. |
AdjIt | it(const leda::graph& G) | introduces a variable it of this class associated with G. The marked node is initialized by n=G.first_node() and the edge by G.first_adj_edge(n). |
AdjIt | it(const leda::graph& G, leda::node n) | |
introduces a variable it of this class marked with n and
associated with G.
The marked edge is initialized by
by G.first_adj_edge(n).
Precondition: n is a node of G. |
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AdjIt | it(const leda::graph& G, leda::node n, leda::edge e) | |
introduces a variable it of this class marked with n
and e
and associated with G.
Precondition: n is a node and e an edge of G and source(e)=n. |
Operations
void | it.init(const graphtype& G) | |
associates it with G and marks it with n'=G.first_node() and G.first_adj_edge(n'). | ||
void | it.init(const graphtype& G, const nodetype& n) | |
associates it with G and marks it with
n and G.first_adj_edge(v).
Precondition: n is a node of G. |
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void | it.init(const graphtype& G, const nodetype& n, const edgetype& e) | |
associates it with G and marks it with
n and e.
Precondition: n is a node and e an edge of G and source(e)=n. |
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void | it.update(leda::edge e) | it marks e afterwards. |
void | it.reset() | resets it to G.first_adj_edge(n) where G and n are the marked node and associated graph. |
void | it.insert(const AdjIt& other) | |
creates a new edge from the marked node of it to the marked node of other. it is marked with the new edge afterwards. The marked node of it does not change. | ||
void | it.del() | deletes the marked leaving edge, i.e. it.valid() returns false afterwards.
Precondition: it.valid() returns true. |
void | it.reset_end() | resets it to G.last_adj_edge(n) where G and n are the marked node and associated graph. |
void | it.make_invalid() | makes it invalid, i.e. it.valid() will be false afterwards and it marks no node. |
void | it.update(leda::node n) | it marks n and the first leaving edge of n afterwards. |
void | it.update(leda::node n, leda::edge e) | |
it marks n and e afterwards. | ||
AdjIt& | it = const AdjIt& it2 | assigns it2 to it. This method returns a reference to it. |
bool | it == const AdjIt& it2 | returns true if and only if it and it2 are equal, i.e. if the marked nodes and edges are equal. |
bool | it.has_node() | returns true if and only if it marks a node. |
bool | it.eol() | returns !it.valid() which is true if and only if there is no successor edge left, i.e. if all edges of the edge set are passed (eol: end of list). |
bool | it.valid() | returns true if and only if end of sequence not yet passed, i.e. if there is an edge in the edge set that was not yet passed. |
leda::edge | it.get_edge() | returns the marked edge or nil if it.valid() returns false. |
leda::node | it.get_node() | returns the marked node or nil if it.has_node() returns false. |
const leda::graph& | it.get_graph() | returns the associated graph. |
AdjIt | it.curr_adj() | If the currently
associated edge leaves the marked node, this method returns a
new adjacency iterator that is associated with n'=target(e) and G.first_adj_edge(n')
where G is the associated graph.
Otherwise it returns
a new adjacency iterator that is
associated with n'=source(e) and G.first_in_edge(n')
where G is the associated graph.
Precondition: it.valid() returns true. |
AdjIt& | ++it | performs one step forward in the list of incident edges of the marked node.
If the formerly marked edge was a leaving edge and there
is no successor edge, it is associated to G.first_in_edge(n)
where G and n are the associated graph and node.
If the formerly marked edge was an incoming edge and there
is no successor edge,
it.eol() will be true afterwards.
This method returns a reference to it.
Precondition: it.valid() returns true. |
AdjIt& | -it | performs one step backward in the list of incident edges of the marked node.
If the formerly marked edge was an incoming edge and there
is no predecessor edge, it is associated to G.last_adj_edge(n)
where G and n are the associated graph and node.
If the formerly marked edge was a leaving edge and there
is no successor edge,
it.eol() will be true afterwards.
This method returns a reference to it.
Precondition: it.valid() returns true. |
Implementation
Creation of an iterator and all methods take constant time.