Graph traversal: Difference between revisions

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== Remarks ==
== Remarks ==


# For the purpose of graph traversal, an undirected graph may be viewed as a directed graph: Replace each edge <math>\{v,w\}</math> by two arcs, <math>(v,w)<math> and <math>(w,v)</math>.
# For the purpose of graph traversal, an undirected graph may be viewed as a directed graph: Replace each edge <math>\{v,w\}</math> by two arcs, <math>(v,w)</math> and <math>(w,v)</math>.
# It may be reasonable to implement a graph traversal algorithm in the form of an iterator, which returns the nodes one-by-one.
# It may be reasonable to implement a graph traversal algorithm in the form of an iterator, which returns the nodes one-by-one.
# [[Dijkstra|Dijkstra's algorithm]] may be implemented as a graph traversal that returns the nodes in ascending order of  their distances.
# [[Dijkstra|Dijkstra's algorithm]] may be implemented as a graph traversal that returns the nodes in ascending order of  their distances.

Revision as of 09:32, 10 October 2014

Input

  1. A directed graph [math]\displaystyle{ G=(V,A) }[/math].
  2. A start node [math]\displaystyle{ s\in V }[/math].


Output

A sequence of all nodes of [math]\displaystyle{ G }[/math] that can be reached from [math]\displaystyle{ s }[/math] via paths in [math]\displaystyle{ G }[/math].

Known algorithms

  1. Depth-first search
  2. Breadth-first search

Remarks

  1. For the purpose of graph traversal, an undirected graph may be viewed as a directed graph: Replace each edge [math]\displaystyle{ \{v,w\} }[/math] by two arcs, [math]\displaystyle{ (v,w) }[/math] and [math]\displaystyle{ (w,v) }[/math].
  2. It may be reasonable to implement a graph traversal algorithm in the form of an iterator, which returns the nodes one-by-one.
  3. Dijkstra's algorithm may be implemented as a graph traversal that returns the nodes in ascending order of their distances.