Skip to content

[WIP] Support undirected graphs for Algorithm\ShortestPath #79

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
clue wants to merge 14 commits into from
Closed

[WIP] Support undirected graphs for Algorithm\ShortestPath #79

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
14 commits
Select commit Hold shift + click to select a range
907c826
Add some tests for undirected graphs
clue Nov 14, 2013
8c3eef8
Improve documentation on (hidden) undirected cycles
clue Nov 14, 2013
cd23aed
First step to support undirected graphs by exposing predecessors
clue Nov 14, 2013
e35803b
Use a createResult() for a dedicated Result interface
clue Dec 30, 2013
328b6a5
Move everything into ShortestPath\SingleSource
clue Dec 31, 2013
d4917fc
Remove the BC layer for Algorithm\ShortestPath
clue Dec 31, 2013
b1ec9db
Remove getGraph() from public interface
clue Dec 31, 2013
f2bd334
Avoid unnecessary edge lookups and use VerticesMap for performance
clue Dec 31, 2013
de61169
Rename concrete result implementation
clue Dec 31, 2013
d4980d0
Use an interface instead of an abstract class for Base
clue Dec 31, 2013
7ff7e16
Merge branch 'master' into shortestpath-undirected
clue Dec 31, 2013
c1377b4
Rework getting edges for predecessors
clue Dec 31, 2013
0b4fe45
Simplify getting all Edges (only on-demand)
clue Dec 31, 2013
cfccf13
Simplify calculating distances
clue Dec 31, 2013
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 5 additions & 6 deletions lib/Fhaculty/Graph/Algorithm/DetectNegativeCycle.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,12 +4,11 @@

use Fhaculty\Graph\Algorithm\BaseGraph;
use Fhaculty\Graph\Exception\UnderflowException;

use Fhaculty\Graph\Graph;
use Fhaculty\Graph\Vertex;
use Fhaculty\Graph\Walk;
use Fhaculty\Graph\Exception\NegativeCycleException;
use Fhaculty\Graph\Algorithm\ShortestPath\MooreBellmanFord as SpMooreBellmanFord;
use Fhaculty\Graph\Algorithm\ShortestPath\SingleSource\MooreBellmanFord;

class DetectNegativeCycle extends BaseGraph
{
Expand Down Expand Up @@ -41,18 +40,18 @@ public function hasCycleNegative()
*/
public function getCycleNegative()
{
$alg = new MooreBellmanFord();

// remember vertices already visited, as they can not lead to a new cycle
$verticesVisited = array();
// check for all vertices
foreach ($this->graph->getVertices()->getMap() as $vid => $vertex) {
// skip vertices already visited
if (!isset($verticesVisited[$vid])) {
// start MBF algorithm on current vertex
$alg = new SpMooreBellmanFord($vertex);

try {
// start MBF algorithm on current vertex
// try to get all connected vertices (or throw new cycle)
foreach ($alg->getVertices()->getIds() as $vid) {
foreach ($alg->createResult($vertex)->getVertices()->getIds() as $vid) {
// getting connected vertices succeeded, so skip over all of them
$verticesVisited[$vid] = true;
// no cycle found, check next vertex...
Expand Down
7 changes: 4 additions & 3 deletions lib/Fhaculty/Graph/Algorithm/MaxFlow/EdmondsKarp.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@

use Fhaculty\Graph\Exception\OutOfBoundsException;

use Fhaculty\Graph\Algorithm\ShortestPath\BreadthFirst;
use Fhaculty\Graph\Algorithm\ShortestPath\SingleSource\BreadthFirst;

use Fhaculty\Graph\Exception\InvalidArgumentException;

Expand Down Expand Up @@ -71,15 +71,16 @@ public function createGraph()
$idA = $this->startVertex->getId();
$idB = $this->destinationVertex->getId();

$alg = new BreadthFirst();

do {
// Generate new residual graph and repeat
$residualAlgorithm = new ResidualGraph($graphResult);
$graphResidual = $residualAlgorithm->createGraph();

// 1. Search _shortest_ (number of hops and cheapest) path from s -> t
$alg = new BreadthFirst($graphResidual->getVertex($idA));
try {
$pathFlow = $alg->getWalkTo($graphResidual->getVertex($idB));
$pathFlow = $alg->createResult($graphResidual->getVertex($idA))->getWalkTo($graphResidual->getVertex($idB));
} catch (OutOfBoundsException $e) {
$pathFlow = NULL;
}
Expand Down
287 changes: 0 additions & 287 deletions lib/Fhaculty/Graph/Algorithm/ShortestPath/Base.php
View file
Open in desktop

This file was deleted.

Loading