Breadth-first search

docs/choice-dictionary.md

@@ -30,15 +30,14 @@ delete cd;
 ```
 <br>
 
-Iterator
+ChoiceDictionaryIterator
 ===
 
-An Iterator is used to iterate through all bits set to 1 in a choice dictionary.
-It supports the so-called *more* operation that returns true if the choice dictionary contains more bits set to 1, aswell as the *next* operation that returns the index of the next arbitrary bit.<br>
-If there are changes made to the choice dictionary during the iteration process, the iterator may return wrong results.
+A ChoiceDictionaryIterator is used to iterate through all bits set to 1 in a choice dictionary.
+It supports the so-called *more* operation that returns true if the choice dictionary contains more bits set to 1, aswell as the *next* operation that returns the index of the next arbitrary bit.
 
 ## Operations
-* init: Initializes the Iterator.
+* init: Initializes the ChoiceDictionaryIterator.
 * more: Returns true if there are more bits set to 1.
 * next: Returns the next arbitrary bit position that is set to 1.
 
@@ -49,7 +48,7 @@ If there are changes made to the choice dictionary during the iteration process,
 
 ```cpp
 ChoiceDictionary* cd = new ChoiceDictionary(12);
-Iterator* it = new Iterator(cd);
+ChoiceDictionaryIterator* it = new ChoiceDictionaryIterator(cd);
 cd->insert(0); // Indexing beginns with 0
 cd->insert(4);
 cd->insert(7);

include/sealib/_types.h

@@ -1,11 +1,20 @@
 #ifndef SEALIB__TYPES_H_
 #define SEALIB__TYPES_H_
-#include <tuple>
 
 // the standard numeric type (used mainly for node names)
 typedef unsigned int uint;
 
 // a pair of numbers (used mainly for stack management)
-typedef std::tuple<uint, uint> Pair;
+// typedef std::tuple<uint, uint> Pair;
+class Pair {
+ private:
+  uint v1, v2;
+
+ public:
+  Pair() : v1(), v2() {}
+  Pair(uint a, uint b) : v1(a), v2(b) {}
+  uint head() { return v1; }
+  uint tail() { return v2; }
+};
 
 #endif  // SEALIB__TYPES_H_

include/sealib/basicgraph.h

@@ -25,6 +25,8 @@ class Basicgraph : public Graph {
      */
     Basicgraph(Node *_nodes, unsigned int _order);
 
+    ~Basicgraph();
+
     /**
      * Getter for a specific node in the nodes array.
      * @param u index in the nodes array.

include/sealib/bfs.h

@@ -0,0 +1,85 @@
+#ifndef SEALIB_BFS_H_
+#define SEALIB_BFS_H_
+#include <stdexcept>
+#include <vector>
+#include "sealib/_types.h"
+#include "sealib/compactarray.h"
+#include "sealib/graph.h"
+#include "sealib/iterator.h"
+
+#define BFS_WHITE 0
+#define BFS_GRAY1 1
+#define BFS_GRAY2 2
+#define BFS_BLACK 3
+
+typedef void (*UserFunc1)(uint);
+typedef void (*UserFunc2)(uint, uint);
+
+#define BFS_NOP_PROCESS (UserFunc1)0
+#define BFS_NOP_EXPLORE (UserFunc2)0
+
+namespace Sealib {
+/**
+ * Run a breadth-first search over a given graph, while executing the two
+ * given user functions.
+ * EFFICIENCY: O(n+m) time, O(n) bits
+ *
+ * The BFS is implemented as an iterator. To start the iterator, call init().
+ * To see if there are more results in this component, call more().
+ * To get the next result, call next().
+ * To move the search to a possible next component, call nextComponent().
+ */
+class BFS : Iterator<Pair> {
+ public:
+  /**
+   * Initialize or reset the BFS to the beginning.
+   */
+  void init() override;
+
+  /**
+   * Check if there is a component that has not been evaluated. If so, the BFS
+   * will continue there.
+   * @return true if a component was found, false if all nodes have been
+   * evaluated
+   */
+  bool nextComponent();
+
+  /**
+   * @return true if this component has unevaluated nodes, false if the
+   * component is all black
+   */
+  bool more() override;
+
+  /**
+   * Get the next node from the current component.
+   * @return a tuple (u,d) where d is the distance of u to the component's
+   * starting node
+   * @throws std::logic_error if no next node is available
+   */
+  Pair next() override;
+
+  /**
+   * Create a new BFS iterator.
+  * @param g the graph to run the BFS over
+  * @param preprocess to be executed before processing a node u
+  * @param preexplore to be executed before exploring an edge (u,v)
+  */
+  BFS(Graph *graph, UserFunc1 pp, UserFunc2 pe);
+
+  ~BFS();
+
+ private:
+  Graph *g;
+  uint n;
+  CompactArray *color;
+  uint u, dist;
+  unsigned innerGray, outerGray;
+  UserFunc1 preprocess;
+  UserFunc2 preexplore;
+
+  bool hasGrayNode();
+  uint getGrayNode();
+};
+
+}  // namespace Sealib
+#endif  // SEALIB_BFS_H_

include/sealib/choicedictionaryiterator.h

@@ -0,0 +1,61 @@
+#ifndef SEALIB_CHOICEDICTIONARYITERATOR_H_
+#define SEALIB_CHOICEDICTIONARYITERATOR_H_
+
+#include "sealib/iterator.h"
+#include "sealib/choicedictionary.h"
+
+#define SHIFT_OFFSET 1UL
+
+namespace Sealib {
+/**
+ * Iteration class to return all bit positions of a choice dictionary that
+ * are set to 1.
+ *
+ * @author Dennis Appel
+ */
+class ChoiceDictionaryIterator : Iterator<unsigned long int> {
+ private:
+    /**
+     * @param primaryWord Value of the currently used word in primary.
+     * @param secondaryWord Value of the currently used word in secondary.
+     * @param primaryIndex Index of the currently used word in primary.
+     * @param secondaryIndex Index of the currently used word in secondary.
+     * @param pointer currently used pointer Position.
+     * @param choicedictionary Pointer to an existing choice dictionary.
+     */
+    unsigned long int primaryWord, secondaryWord, pointer, primaryIndex, secondaryIndex;
+    ChoiceDictionary *choicedictionary;
+
+    bool hasNextSecondary();
+
+    void setNextSecondaryWord();
+
+    void setNextPrimaryWord();
+
+ public:
+    /**
+     * Creates an Iterator for a choice dictionary.
+     * @param _choicedictionary Pointer to an existing choice dictionary.
+     */
+    explicit ChoiceDictionaryIterator(ChoiceDictionary *_choicedictionary);
+
+    /**
+     * Initializes the iterator.
+     */
+    void init();
+
+    /**
+     * Returns true when there are more bits that are set to 1 in the choice
+     * dictionary and updates the used words if neccessary.
+     */
+    bool more();
+
+    /**
+     * Returns the next index of a bit set to 1.
+     */
+    unsigned long int next();
+
+    ~ChoiceDictionaryIterator();
+};
+}  // namespace Sealib
+#endif  // SEALIB_CHOICEDICTIONARYITERATOR_H_

include/sealib/dfs.h

@@ -1,8 +1,8 @@
 #ifndef SEALIB_DFS_H_
 #define SEALIB_DFS_H_
 
+#include <sstream>
 #include <stack>
-#include <tuple>
 #include "sealib/_types.h"
 #include "sealib/compactarray.h"
 #include "sealib/graph.h"
@@ -37,7 +37,6 @@ namespace Sealib {
  *  - standardDFS: the normal DFS, uses implicit recursion stack
  *  - nBitDFS: space-efficient DFS, explicit segmented stack
  *
- * @author Simon Heuser
  */
 class DFS {
  public:
@@ -49,6 +48,7 @@ class DFS {
    * @param preexplore to be executed before exploring an edge (u,v)
    * @param postexplore to be executed after exploring an edge (u,v)
    * @param postprocess to be executed after processing a node u
+   * @author Simon Heuser
    */
   static void standardDFS(Graph *g, UserFunc1 preprocess, UserFunc2 preexplore,
                           UserFunc2 postexplore, UserFunc1 postprocess);
@@ -61,18 +61,22 @@ class DFS {
    * @param preexplore to be executed before exploring an edge (u,v)
    * @param postexplore to be executed after exploring an edge (u,v)
    * @param postprocess to be executed after processing a node u
+   * @author Simon Heuser
    */
   static void nBitDFS(Graph *g, UserFunc1 preprocess, UserFunc2 preexplore,
                       UserFunc2 postexplore, UserFunc1 postprocess);
 
-    /**
-     * Runs an inplace DFS in linear time over a graph that is given in a special representation. <br>
-     * EFFICIENCY: O(n+m) time, O(log n) bits
-     * @param graph Graph A graph in a swapped begin pointer representation.
-     * @param startVertex startVertex The begin of the DFS tree.
-     */
-    static void runLinearTimeInplaceDFS(unsigned int* graph, UserFunc1 preProcess,
-                                        UserFunc1 postProcess, unsigned int startVertex);
+  /**
+   * Runs an inplace DFS in linear time over a graph that is given in a special
+   * representation. <br>
+   * EFFICIENCY: O(n+m) time, O(log n) bits
+   * @param graph Graph A graph in a swapped begin pointer representation.
+   * @param startVertex startVertex The begin of the DFS tree.
+   * @author Simon Schniedenharn
+   */
+  static void runLinearTimeInplaceDFS(unsigned int *graph, UserFunc1 preProcess,
+                                      UserFunc1 postProcess,
+                                      unsigned int startVertex);
 };
 }  // namespace Sealib
 #endif  // SEALIB_DFS_H_

include/sealib/graph.h

@@ -28,6 +28,8 @@ class Graph {
     * @return Returns the order of the graph, i.e, the total number of vertices.
     */
     virtual unsigned int getOrder() = 0;
+
+    virtual ~Graph() {}
 };
 }  // namespace Sealib
 #endif  // SEALIB_GRAPH_H_

include/sealib/graphcreator.h

@@ -36,7 +36,7 @@ class GraphCreator {
    * @param order number of nodes the graph should contain
    * @param degreePerNode the degree of each node; the edges will go to any
    * random node
-   * @return the resulting graph G: n = order, m = degreePerNode * order
+   * @return the resulting graph G (n = order, m = degreePerNode*order)
    * @author Simon Heuser
    */
   static Basicgraph *createRandomFixed(unsigned int order,

include/sealib/iterator.h

@@ -1,59 +1,34 @@
 #ifndef SEALIB_ITERATOR_H_
 #define SEALIB_ITERATOR_H_
 
-#include "sealib/choicedictionary.h"
-
-#define SHIFT_OFFSET 1UL
-
 namespace Sealib {
 /**
- * Iteration class to return all bit positions of a choice dictionary that
- * are set to 1.
- * @author Dennis Appel
+ * An iterator interface to be used by several classes in this library.
+ * @param T the element type that this iterator iterates over
+ * @author Simon Heuser
  */
+template <class T>
 class Iterator {
- private:
-    /**
-     * @param primaryWord Value of the currently used word in primary.
-     * @param secondaryWord Value of the currently used word in secondary.
-     * @param primaryIndex Index of the currently used word in primary.
-     * @param secondaryIndex Index of the currently used word in secondary.
-     * @param pointer currently used pointer Position.
-     * @param choicedictionary Pointer to an existing choice dictionary.
-     */
-    unsigned long int primaryWord, secondaryWord, pointer, primaryIndex, secondaryIndex;
-    ChoiceDictionary *choicedictionary;
-
-    bool hasNextSecondary();
-
-    void setNextSecondaryWord();
-
-    void setNextPrimaryWord();
-
  public:
-    /**
-     * Creates an Iterator for a choice dictionary.
-     * @param _choicedictionary Pointer to an existing choice dictionary.
-     */
-    explicit Iterator(ChoiceDictionary *_choicedictionary);
-
-    /**
-     * Initializes the iterator.
-     */
-    void init();
-
-    /**
-     * Returns true when there are more bits that are set to 1 in the choice
-     * dictionary and updates the used words if neccessary.
-     */
-    bool more();
-
-    /**
-     * Returns the next index of a bit set to 1.
-     */
-    unsigned long int next();
-
-    ~Iterator();
+  /**
+   * Initialize the iterator.
+   */
+  virtual void init();
+
+  /**
+   * Check if the iterator has another element that can be retrieved.
+   * @return true if there is another element, false otherwise
+   */
+  virtual bool more();
+
+  /**
+   * Get the next element from this iterator
+   * @return the next element
+   * @throws std::logic_error if there are no more elements
+   */
+  virtual T next();
+
+  virtual ~Iterator() {}
 };
 }  // namespace Sealib
 #endif  // SEALIB_ITERATOR_H_

src/basicgraph.cpp

@@ -18,3 +18,7 @@ unsigned int Basicgraph::getOrder() {
 }
 
 Basicgraph::Basicgraph(Node *_nodes, unsigned int _order) : nodes(_nodes), order(_order) { }
+
+Basicgraph::~Basicgraph() {
+    delete nodes;
+}