Scippy

SCIP

Solving Constraint Integer Programs

Detailed Description

C implementation of Dijkstra's algorithm.

Author
Thorsten Koch
Marc Pfetsch

Definition in file dijkstra.c.

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "dijkstra.h"

Go to the source code of this file.

Functions

DIJKSTRA_Bool dijkstraGraphIsValid (const DIJKSTRA_GRAPH *G)
 
static DIJKSTRA_Bool dijkstraHeapIsValid (const unsigned int *entry, const unsigned long long *value, const unsigned int *order, const unsigned int used, const unsigned int size)
 
static void dijkstraSiftDown (unsigned int *entry, const unsigned long long *value, unsigned int *order, unsigned int used, unsigned int current)
 
static void dijkstraSiftUp (unsigned int *entry, const unsigned long long *value, unsigned int *order, unsigned int current)
 
unsigned int dijkstra (const DIJKSTRA_GRAPH *G, unsigned int source, unsigned long long *dist, unsigned int *pred, unsigned int *entry, unsigned int *order)
 
unsigned int dijkstraPair (const DIJKSTRA_GRAPH *G, unsigned int source, unsigned int target, unsigned long long *dist, unsigned int *pred, unsigned int *entry, unsigned int *order)
 
unsigned int dijkstraPairCutoff (const DIJKSTRA_GRAPH *G, unsigned int source, unsigned int target, unsigned long long cutoff, unsigned long long *dist, unsigned int *pred, unsigned int *entry, unsigned int *order)
 
unsigned int dijkstraPairCutoffIgnore (const DIJKSTRA_GRAPH *G, unsigned int source, unsigned int target, unsigned int *ignore, unsigned long long cutoff, unsigned long long *dist, unsigned int *pred, unsigned int *entry, unsigned int *order)
 

Function Documentation

◆ dijkstraGraphIsValid()

DIJKSTRA_Bool dijkstraGraphIsValid ( const DIJKSTRA_GRAPH G)

◆ dijkstraHeapIsValid()

static DIJKSTRA_Bool dijkstraHeapIsValid ( const unsigned int *  entry,
const unsigned long long *  value,
const unsigned int *  order,
const unsigned int  used,
const unsigned int  size 
)
static

Check whether heap is valid.

Note
Sift up/down do not use order, only for the last the changed one is entered.
Parameters
entryentries of heap
valuevalues in heap
orderorder of entries
usednumber of used entries
sizesize of entry array

Definition at line 83 of file dijkstra.c.

References FALSE, NULL, and TRUE.

Referenced by dijkstra(), dijkstraPair(), dijkstraPairCutoff(), and dijkstraPairCutoffIgnore().

◆ dijkstraSiftDown()

static void dijkstraSiftDown ( unsigned int *  entry,
const unsigned long long *  value,
unsigned int *  order,
unsigned int  used,
unsigned int  current 
)
static

Moves an entry down in the vector until the sorting is valid again.

Parameters
entryentries of heap
valuevalues in heap
orderorder of entries
usednumber of used entries
currentcurrent entry to be sifted

Definition at line 112 of file dijkstra.c.

Referenced by dijkstra(), dijkstraPair(), dijkstraPairCutoff(), and dijkstraPairCutoffIgnore().

◆ dijkstraSiftUp()

static void dijkstraSiftUp ( unsigned int *  entry,
const unsigned long long *  value,
unsigned int *  order,
unsigned int  current 
)
static

Moves an entry up in the vector until the sorting is valid again.

Parameters
entryentries of heap
valuevalues in heap
orderorder of entries
currentcurrent entry to be sifted

Definition at line 157 of file dijkstra.c.

Referenced by dijkstra(), dijkstraPair(), dijkstraPairCutoff(), and dijkstraPairCutoffIgnore().

◆ dijkstra()

unsigned int dijkstra ( const DIJKSTRA_GRAPH G,
unsigned int  source,
unsigned long long *  dist,
unsigned int *  pred,
unsigned int *  entry,
unsigned int *  order 
)

Dijkstra's algorithm for shortest paths from a single source using binary heaps

Parameters
Gdirected graph
sourcesource node
distnode distances (allocated by user)
prednode predecessors in final shortest path tree (allocated by user)
entrytemporary storage (for each node - must be allocated by user)
ordertemporary storage (for each node - must be allocated by user)

Definition at line 190 of file dijkstra.c.

References DIJKSTRA_FARAWAY, DIJKSTRA_UNUSED, dijkstraGraphIsValid(), dijkstraHeapIsValid(), dijkstraSiftDown(), dijkstraSiftUp(), DIJKSTRA_Graph::head, DIJKSTRA_Graph::nodes, NULL, DIJKSTRA_Graph::outbeg, BMS_BufMem::used, and DIJKSTRA_Graph::weight.

◆ dijkstraPair()

unsigned int dijkstraPair ( const DIJKSTRA_GRAPH G,
unsigned int  source,
unsigned int  target,
unsigned long long *  dist,
unsigned int *  pred,
unsigned int *  entry,
unsigned int *  order 
)

Dijkstra's algorithm for shortest paths between a pair of nodes using binary heaps

Parameters
Gdirected graph
sourcesource node
targettarget node
distnode distances (allocated by user)
prednode predecessors in final shortest path tree (allocated by user)
entrytemporary storage (for each node - must be allocated by user)
ordertemporary storage (for each node - must be allocated by user)

Definition at line 290 of file dijkstra.c.

References DIJKSTRA_FARAWAY, DIJKSTRA_UNUSED, dijkstraGraphIsValid(), dijkstraHeapIsValid(), dijkstraSiftDown(), dijkstraSiftUp(), DIJKSTRA_Graph::head, DIJKSTRA_Graph::nodes, NULL, DIJKSTRA_Graph::outbeg, BMS_BufMem::used, and DIJKSTRA_Graph::weight.

◆ dijkstraPairCutoff()

unsigned int dijkstraPairCutoff ( const DIJKSTRA_GRAPH G,
unsigned int  source,
unsigned int  target,
unsigned long long  cutoff,
unsigned long long *  dist,
unsigned int *  pred,
unsigned int *  entry,
unsigned int *  order 
)

Dijkstra's algorithm for shortest paths between a pair of nodes using binary heaps and truncated at cutoff

Parameters
Gdirected graph
sourcesource node
targettarget node
cutoffif the distance of a node reached this value, we truncate the search
distnode distances (allocated by user)
prednode predecessors in final shortest path tree (allocated by user)
entrytemporary storage (for each node - must be allocated by user)
ordertemporary storage (for each node - must be allocated by user)

Definition at line 396 of file dijkstra.c.

References DIJKSTRA_FARAWAY, DIJKSTRA_UNUSED, dijkstraGraphIsValid(), dijkstraHeapIsValid(), dijkstraSiftDown(), dijkstraSiftUp(), DIJKSTRA_Graph::head, DIJKSTRA_Graph::nodes, NULL, DIJKSTRA_Graph::outbeg, BMS_BufMem::used, and DIJKSTRA_Graph::weight.

Referenced by separateGLS().

◆ dijkstraPairCutoffIgnore()

unsigned int dijkstraPairCutoffIgnore ( const DIJKSTRA_GRAPH G,
unsigned int  source,
unsigned int  target,
unsigned int *  ignore,
unsigned long long  cutoff,
unsigned long long *  dist,
unsigned int *  pred,
unsigned int *  entry,
unsigned int *  order 
)

Dijkstra's algorithm for shortest paths between a pair of nodes ignoring nodes, using binary heaps, and truncated at cutoff

Parameters
Gdirected graph
sourcesource node
targettarget node
ignoremarking nodes to be ignored (if value is nonzero)
cutoffif the distance of a node reached this value, we truncate the search
distnode distances (allocated by user)
prednode predecessors in final shortest path tree (allocated by user)
entrytemporary storage (for each node - must be allocated by user)
ordertemporary storage (for each node - must be allocated by user)

Definition at line 507 of file dijkstra.c.

References DIJKSTRA_FARAWAY, DIJKSTRA_UNUSED, dijkstraGraphIsValid(), dijkstraHeapIsValid(), dijkstraSiftDown(), dijkstraSiftUp(), DIJKSTRA_Graph::head, DIJKSTRA_Graph::nodes, NULL, DIJKSTRA_Graph::outbeg, BMS_BufMem::used, and DIJKSTRA_Graph::weight.

Referenced by separateGLS().