[Lemon-commits] [lemon_svn] jacint: r238 - hugo/trunk/src/work/jacint

Lemon SVN svn at lemon.cs.elte.hu
Mon Nov 6 20:38:17 CET 2006


Author: jacint
Date: Thu Mar 11 13:55:50 2004
New Revision: 238

Added:
   hugo/trunk/src/work/jacint/fib_heap.h
Modified:
   hugo/trunk/src/work/jacint/dijkstra.cc
   hugo/trunk/src/work/jacint/dijkstra.h

Log:
*** empty log message ***


Modified: hugo/trunk/src/work/jacint/dijkstra.cc
==============================================================================
--- hugo/trunk/src/work/jacint/dijkstra.cc	(original)
+++ hugo/trunk/src/work/jacint/dijkstra.cc	Thu Mar 11 13:55:50 2004
@@ -21,17 +21,23 @@
   
   double pre_time=currTime();
     Dijkstra<ListGraph, int> dijkstra_test(G, s, cap);
+    dijkstra_test.run();
   double post_time=currTime();
     
   std::cout << "running time: " << post_time-pre_time << " sec"<< std::endl; 
  
+  int hiba=0;
   EachEdgeIt e;
-
   for ( G.getFirst(e) ; G.valid(e); G.next(e) ) {
     NodeIt u=G.tail(e);
     NodeIt v=G.head(e);
-    assert ( dijkstra_test.dist(v) - dijkstra_test.dist(u) <= cap.get(e) );
+    if ( dijkstra_test.dist(v) - dijkstra_test.dist(u) > cap.get(e) ) {
+      std::cout<<"Hiba: "<<dijkstra_test.dist(v) - dijkstra_test.dist(u) - cap.get(e)<<std::endl;
+      ++hiba;
+    }
   }
 
+  std::cout << "Hibas elek szama: " << hiba << " a " << G.edgeNum() <<"-bol."<< std::endl;
+
   return 0;
 }

Modified: hugo/trunk/src/work/jacint/dijkstra.h
==============================================================================
--- hugo/trunk/src/work/jacint/dijkstra.h	(original)
+++ hugo/trunk/src/work/jacint/dijkstra.h	Thu Mar 11 13:55:50 2004
@@ -2,29 +2,24 @@
 /* 
  *template <Graph, T, Heap=FibHeap>
  *
- *
  *Constructor: 
  *
  *Dijkstra(Graph G, NodeIt s, Graph::EdgeMap<T> length)
  *
  *
- *
  *Member functions:
  *
  *void run()
  *
  *  The following function should be used after run() was already run.
  *
- *
  *T dist(NodeIt v) : returns the distance from s to v. 
  *   It is 0 if v is not reachable from s.
  *
- *
  *EdgeIt pred(NodeIt v) : returns the last edge 
  *   of a shortest s-v path. Returns an invalid iterator 
  *   if v=s or v is not reachable from s.
  *
- *
  *bool reach(NodeIt v) : true iff v is reachable from s
  *
  */
@@ -76,9 +71,9 @@
 
 	  NodeIt v=heap.top(); 
 	  T oldvalue=heap.get(v);
-	  distance.set(v, oldvalue);
 	  heap.pop();
-	  
+	  distance.set(v, oldvalue);
+
 	  OutEdgeIt e;
 	  for( G.getFirst(e,v); G.valid(e); G.next(e)) {
 	    NodeIt w=G.bNode(e); 
@@ -88,7 +83,6 @@
 		reached.set(w,true);
 		heap.push(w,oldvalue+length.get(e)); 
 		predecessor.set(w,e);
-
 	      } else if ( oldvalue+length.get(e) < heap.get(w) ) {
 		predecessor.set(w,e);
 		heap.decrease(w, oldvalue+length.get(e)); 
@@ -114,9 +108,9 @@
       bool reach(NodeIt v) {
 	return reached.get(v);
       }
-
+      
     };
-
+  
 }
 
 #endif

Added: hugo/trunk/src/work/jacint/fib_heap.h
==============================================================================
--- (empty file)
+++ hugo/trunk/src/work/jacint/fib_heap.h	Thu Mar 11 13:55:50 2004
@@ -0,0 +1,400 @@
+// -*- C++ -*-
+/*
+ *template <typename Item, 
+ *          typename Prio, 
+ *          typename ItemIntMap, 
+ *          typename Compare = std::less<Prio> >
+ * 
+ *constructors:
+ *
+ *FibHeap(ItemIntMap),   FibHeap(ItemIntMap, Compare)
+ *
+ *Member functions:
+ *
+ *int size() : returns the number of elements in the heap
+ *
+ *bool empty() : true iff size()=0
+ *
+ *void set(Item, Prio) : calls push(Item, Prio) if Item is not
+ *     in the heap, and calls decrease/increase(Item, Prio) otherwise
+ *
+ *void push(Item, Prio) : pushes Item to the heap with priority Prio. Item
+ *     mustn't be in the heap.
+ *
+ *Item top() : returns the Item with least Prio
+ *
+ *Prio prio() : returns the least Prio
+ *  
+ *Prio get(Item) : returns Prio of Item
+ *
+ *void pop() : deletes the Item with least Prio
+ *
+ *void erase(Item) : deletes Item from the heap if it was already there
+ *
+ *void decrease(Item, P) : decreases prio of Item to P. 
+ *     Item must be in the heap with prio at least P.
+ *
+ *void increase(Item, P) : sets prio of Item to P. 
+ *
+ *state_enum state(Item) : returns PRE_HEAP if Item has not been in the 
+ *     heap until now, IN_HEAP if it is in the heap at the moment, and 
+ *     POST_HEAP otherwise. In the latter case it is possible that Item
+ *     will get back to the heap again. 
+ *
+ *In Fibonacci heaps, increase and erase are not efficient, in case of
+ *many calls to these operations, it is better to use bin_heap.
+ */
+
+#ifndef FIB_HEAP_H
+#define FIB_HEAP_H
+
+#include <vector>
+#include <functional>
+#include <math.h>
+
+namespace hugo {
+  
+  template <typename Item, typename Prio, typename ItemIntMap, 
+    typename Compare = std::less<Prio> >
+ 
+  class FibHeap {
+  
+    typedef Prio PrioType;
+    
+    class store;
+    
+    std::vector<store> container;
+    int minimum;
+    bool blank;
+    ItemIntMap &iimap;
+    Compare comp;
+
+    enum state_enum {
+      IN_HEAP = 0,
+      PRE_HEAP = -1,
+      POST_HEAP = -2
+    };
+    
+  public :
+    
+    FibHeap(ItemIntMap &_iimap) : minimum(), blank(true), iimap(_iimap) {} 
+    FibHeap(ItemIntMap &_iimap, const Compare &_comp) : minimum(), 
+      blank(true), iimap(_iimap), comp(_comp) {}
+    
+    
+    int size() const {
+      int s=0;
+      for ( unsigned int i=0; i!=container.size(); ++i )
+	if ( container[i].in ) ++s;
+      return s; 
+    }
+
+
+    bool empty() const { return blank; }
+
+
+    void set (Item const it, PrioType const value) {
+      int i=iimap.get(it);
+      if ( i >= 0 && container[i].in ) {
+	if ( !comp(container[i].prio, value) ) decrease(it, value); 
+	if ( comp(container[i].prio, value) ) increase(it, value); 
+      } else push(it, value);
+    }
+    
+
+    void push (Item const it, PrioType const value) {
+      int i=iimap.get(it);      
+      if ( i < 0 ) {
+	int s=container.size();
+	iimap.set( it, s );	
+	store st;
+	st.name=it;
+	container.push_back(st);
+	i=s;
+      } else {
+	container[i].parent=container[i].child=-1;
+	container[i].degree=0;
+	container[i].in=true;
+	container[i].marked=false;
+      }
+
+      if ( !blank ) {
+	container[container[minimum].right_neighbor].left_neighbor=i;
+	container[i].right_neighbor=container[minimum].right_neighbor;
+	container[minimum].right_neighbor=i;
+	container[i].left_neighbor=minimum;
+	if ( !comp( container[minimum].prio, value) ) minimum=i; 
+      } else {
+	container[i].right_neighbor=container[i].left_neighbor=i;
+	minimum=i;	
+	blank=false;
+      }
+      container[i].prio=value;
+    }
+    
+
+    Item top() const {
+      if ( !blank ) { 
+	return container[minimum].name;
+      } else {
+	return Item();
+      }
+    }
+    
+    
+    PrioType prio() const {
+      if ( !blank ) { 
+	return container[minimum].prio;
+      } else {
+	return PrioType();
+      }
+    }
+    
+
+    const PrioType get(const Item& it) const {
+      int i=iimap.get(it);
+      
+      if ( i >= 0 && container[i].in ) { 
+	return container[i].prio;
+      } else {
+	return PrioType();
+      }
+    }
+
+
+
+
+    void pop() {
+      /*The first case is that there are only one root.*/
+      if ( container[minimum].left_neighbor==minimum ) {
+	container[minimum].in=false;
+	if ( container[minimum].degree==0 ) blank=true; 
+	else { 
+	  makeroot(container[minimum].child);
+	  minimum=container[minimum].child;
+	  balance();
+	} 
+      } else {
+	int right=container[minimum].right_neighbor;
+	unlace(minimum);
+	container[minimum].in=false;
+	if ( container[minimum].degree > 0 ) {
+	  int left=container[minimum].left_neighbor;
+	  int child=container[minimum].child;
+	  int last_child=container[child].left_neighbor;
+	
+	  makeroot(child);
+	  
+	  container[left].right_neighbor=child;
+	  container[child].left_neighbor=left;
+	  container[right].left_neighbor=last_child;
+	  container[last_child].right_neighbor=right;
+	}
+	minimum=right;
+	balance();
+      } // the case where there are more roots
+    }
+
+    
+    void erase (const Item& it) {
+      int i=iimap.get(it);
+      
+      if ( i >= 0 && container[i].in ) { 
+	
+       if ( container[i].parent!=-1 ) {
+	 int p=container[i].parent;
+	 cut(i,p);	    
+	 cascade(p);
+	 minimum=i;     //As if its prio would be -infinity
+       }
+       pop();
+     }
+   }
+    
+
+    void decrease (Item it, PrioType const value) {
+      int i=iimap.get(it);
+      container[i].prio=value;
+      int p=container[i].parent;
+      
+      if ( p!=-1 && comp(value, container[p].prio) ) {
+	cut(i,p);	    
+	cascade(p);
+	if ( comp(value, container[minimum].prio) ) minimum=i; 
+      }
+    }
+   
+
+    void increase (Item it, PrioType const value) {
+      erase(it);
+      push(it, value);
+    }
+
+
+    state_enum state(const Item &it) const {
+      int i=iimap.get(it);
+      if( i>=0 ) {
+	if ( container[i].in ) i=0;
+	else i=-2; 
+      }
+      return state_enum(i);
+    }
+
+
+  private:
+    
+    void balance() {      
+
+    int maxdeg=int( floor( 2.08*log(double(container.size()))))+1;
+  
+    std::vector<int> A(maxdeg,-1); 
+    
+    /*
+     *Recall that now minimum does not point to the minimum prio element.
+     *We set minimum to this during balance().
+     */
+    int anchor=container[minimum].left_neighbor; 
+    int next=minimum; 
+    bool end=false; 
+    	
+       do {
+	int active=next;
+	if ( anchor==active ) end=true;
+	int d=container[active].degree;
+	next=container[active].right_neighbor;
+
+	while (A[d]!=-1) {	  
+	  if( comp(container[active].prio, container[A[d]].prio) ) {
+	    fuse(active,A[d]); 
+	  } else { 
+	    fuse(A[d],active);
+	    active=A[d];
+	  } 
+	  A[d]=-1;
+	  ++d;
+	}	
+	A[d]=active;
+       } while ( !end );
+
+
+       while ( container[minimum].parent >=0 ) minimum=container[minimum].parent;
+       int s=minimum;
+       int m=minimum;
+       do {  
+	 if ( comp(container[s].prio, container[minimum].prio) ) minimum=s;
+	 s=container[s].right_neighbor;
+       } while ( s != m );
+    }
+
+
+    void makeroot (int c) {
+      int s=c;
+      do {  
+	container[s].parent=-1;
+	s=container[s].right_neighbor;
+      } while ( s != c );
+    }
+    
+
+    void cut (int a, int b) {    
+      /*
+       *Replacing a from the children of b.
+       */
+      --container[b].degree;
+      
+      if ( container[b].degree !=0 ) {
+	int child=container[b].child;
+	if ( child==a ) 
+	  container[b].child=container[child].right_neighbor;
+	unlace(a);
+      }
+      
+      
+      /*Lacing i to the roots.*/
+      int right=container[minimum].right_neighbor;
+      container[minimum].right_neighbor=a;
+      container[a].left_neighbor=minimum;
+      container[a].right_neighbor=right;
+      container[right].left_neighbor=a;
+
+      container[a].parent=-1;
+      container[a].marked=false;
+    }
+
+
+    void cascade (int a) 
+    {
+      if ( container[a].parent!=-1 ) {
+	int p=container[a].parent;
+	
+	if ( container[a].marked==false ) container[a].marked=true;
+	else {
+	  cut(a,p);
+	  cascade(p);
+	}
+      }
+    }
+
+
+    void fuse (int a, int b) {
+      unlace(b);
+      
+      /*Lacing b under a.*/
+      container[b].parent=a;
+
+      if (container[a].degree==0) {
+	container[b].left_neighbor=b;
+	container[b].right_neighbor=b;
+	container[a].child=b;	
+      } else {
+	int child=container[a].child;
+	int last_child=container[child].left_neighbor;
+	container[child].left_neighbor=b;
+	container[b].right_neighbor=child;
+	container[last_child].right_neighbor=b;
+	container[b].left_neighbor=last_child;
+      }
+
+      ++container[a].degree;
+      
+      container[b].marked=false;
+    }
+
+
+    /*
+     *It is invoked only if a has siblings.
+     */
+    void unlace (int a) {      
+      int leftn=container[a].left_neighbor;
+      int rightn=container[a].right_neighbor;
+      container[leftn].right_neighbor=rightn;
+      container[rightn].left_neighbor=leftn;
+    }
+
+
+    class store {
+      friend class FibHeap;
+      
+      Item name;
+      int parent;
+      int left_neighbor;
+      int right_neighbor;
+      int child;
+      int degree;  
+      bool marked;
+      bool in;
+      PrioType prio;
+
+      store() : parent(-1), child(-1), degree(), marked(false), in(true) {} 
+    };
+    
+  };
+  
+} //namespace hugo
+#endif 
+
+
+
+
+
+



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