COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/work/akos/simann.h @ 942:75fdd0c6866d

Last change on this file since 942:75fdd0c6866d was 942:75fdd0c6866d, checked in by Akos Ladanyi, 16 years ago

Naming and coding style fixes and various other changes.

File size: 2.6 KB
Line 
1#ifndef LEMON_SIMANN_H
2#define LEMON_SIMANN_H
3
4namespace lemon {
5
6  const double INFTY = 1e24;
7
8  class SimAnnBase {
9  public:
10    class Controller;
11  private:
12    Controller *controller;
13  protected:
14    double curr_cost;
15    double prev_cost;
16    double best_cost;
17
18    virtual void mutate() = 0;
19    virtual void revert() = 0;
20    virtual void saveAsBest() = 0;
21  public:
22    SimAnnBase() {
23      curr_cost = prev_cost = best_cost = INFTY;
24    }
25    void setController(Controller &_controller) { controller = &_controller; }
26    double getBestCost() { return best_cost; }
27    void run() {
28      while (controller->next()) {
29        mutate();
30        if (controller->accept(prev_cost - curr_cost)) {
31          controller->acceptEvent();
32          if (curr_cost < best_cost) {
33            saveAsBest();
34            controller->improveEvent();
35          }
36        }
37        else {
38          revert();
39          controller->rejectEvent();
40        }
41      }
42    }
43
44    class Controller {
45    public:
46      virtual void acceptEvent() {}
47      virtual void improveEvent() {}
48      virtual void rejectEvent() {}
49      virtual bool next() = 0;
50      virtual bool accept(double cost_diff) = 0;
51    };
52  };
53
54  template <typename E>
55  class SimAnn : public SimAnnBase {
56  private:
57    E *curr_ent;
58    E *prev_ent;
59    E *best_ent;
60  public:
61    SimAnn() : SimAnnBase() {}
62    void setEntity(E &Ent) {
63      curr_ent = new E(Ent);
64      prev_ent = new E(Ent);
65      best_ent = new E(Ent);
66    }
67    E getBestEntity() { return *best_ent; }
68    void mutate() {
69      *prev_ent = *curr_ent;
70      prev_cost = curr_cost;
71      curr_cost = curr_ent->mutate();
72    }
73    void revert() {
74      E *tmp = curr_ent;
75      curr_ent = prev_ent;
76      prev_ent = tmp;
77      curr_cost = prev_cost;
78    }
79    void saveAsBest() {
80      *best_ent = *curr_ent;
81      best_cost = curr_cost;
82    }
83  };
84
85  class EntitySkeleton {
86  public:
87    // returns the new cost
88    double mutate() { return 0.0; }
89  };
90
91  template <typename E>
92  class SimAnn2 : public SimAnnBase {
93  private:
94    E *curr_ent;
95    E *best_ent;
96  public:
97    SimAnn2() : SimAnnBase() {}
98    void setEntity(E &Ent) {
99      curr_ent = new E(Ent);
100      best_ent = new E(Ent);
101    }
102    E getBestEntity() { return *best_ent; }
103    void mutate() {
104      curr_ent->mutate();
105    }
106    void revert() {
107      curr_ent->revert();
108    }
109    void saveAsBest() {
110      *best_ent = *curr_ent;
111      best_cost = curr_cost;
112    }
113  };
114
115  class EntitySkeleton2 {
116  public:
117    // returns the new cost
118    double mutate() { return 0.0; }
119    // restores the entity to its previous state i.e. reverts the effects of
120    // the last mutate()
121    void revert() {}
122  };
123
124}
125
126#endif
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