Version 5.0 The LEDA User Manual

OutAdjIt algorithm.curr adj( ) returns the an adjacency iterator that is currently adjacent
to current( ).
bool algorithm.is pred( ) returns true if the current iterator satisfies the dijkstra
condition. Can be used to compute the predecessors.
void algorithm.next( ) performs one iteration of the core loop of the algorithm.
void algorithm.finish algo( )
4. Example
executes the algorithm until finished( ) is true, i.e.
exactly if the priority queue is empty.
Class GIT DIJKSTRA may be used in a deeper layer in a hierarchy of classes and functions.
For example, you may write a function which computes shortes path distances with given
iterators and data accessors:
template
void GIT_dijkstra_core(OutAdjIt s, Length& length, Distance& distance,
PriorityQueue& pq, QueueItem& qi) {
GIT_DIJKSTRA
internal_dijk(length,distance,qi);
internal_dijk.get_queue()=pq;
set(distance,s,distance.value_null);
if (s.valid()) {
internal_dijk.init(s);
internal_dijk.finish_algo();
}
}
In another layer, you would instantiate these iterators and data acessors for a graph and
invoke this function.
5. Implementation
The asymptotic complexity is O(m + n · T (n)), where T (n) is the(possibly amortized)
complexity of a single queue update.
For the priority queues described in Chapter 8.1, it is T (n) = O(log n).