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28 package org.sat4j.opt;
29
30 import org.sat4j.core.VecInt;
31 import org.sat4j.specs.IOptimizationProblem;
32 import org.sat4j.specs.ISolver;
33 import org.sat4j.specs.IVecInt;
34 import org.sat4j.specs.TimeoutException;
35 import org.sat4j.tools.SolverDecorator;
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47 public abstract class AbstractSelectorVariablesDecorator extends
48 SolverDecorator<ISolver> implements IOptimizationProblem {
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50
51
52
53 private static final long serialVersionUID = 1L;
54
55 protected int nborigvars;
56
57 private int nbexpectedclauses;
58
59 protected int nbnewvar;
60
61 protected int[] prevfullmodel;
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63
64
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66 protected int[] prevmodel;
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68
69
70 protected boolean[] prevboolmodel;
71
72 public AbstractSelectorVariablesDecorator(ISolver solver) {
73 super(solver);
74 }
75
76 @Override
77 public int newVar(int howmany) {
78 nborigvars = super.newVar(howmany);
79 return nborigvars;
80 }
81
82 @Override
83 public void setExpectedNumberOfClauses(int nb) {
84 nbexpectedclauses = nb;
85 super.setExpectedNumberOfClauses(nb);
86 super.newVar(nborigvars + nbexpectedclauses);
87 }
88
89 public int getExpectedNumberOfClauses() {
90 return nbexpectedclauses;
91 }
92
93 @Override
94 public void reset() {
95 super.reset();
96 nbnewvar = 0;
97 }
98
99 public boolean admitABetterSolution() throws TimeoutException {
100 return admitABetterSolution(VecInt.EMPTY);
101 }
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105
106 public boolean admitABetterSolution(IVecInt assumps)
107 throws TimeoutException {
108 boolean result = super.isSatisfiable(assumps, true);
109 if (result) {
110 prevboolmodel = new boolean[nVars()];
111 for (int i = 0; i < nVars(); i++) {
112 prevboolmodel[i] = decorated().model(i + 1);
113 }
114 prevfullmodel = super.model();
115 int end = nborigvars - 1;
116 while (Math.abs(prevfullmodel[end]) > nborigvars)
117 end--;
118 prevmodel = new int[end + 1];
119 for (int i = 0; i <= end; i++) {
120 prevmodel[i] = prevfullmodel[i];
121 }
122 calculateObjectiveValue();
123 }
124 return result;
125 }
126
127 abstract void calculateObjectiveValue();
128
129 @Override
130 public int[] model() {
131 return prevmodel;
132 }
133
134 @Override
135 public boolean model(int var) {
136 return prevboolmodel[var - 1];
137 }
138 }