001/*
002 * $Id: CPair.java 5687 2017-01-03 08:44:03Z kredel $
003 */
004
005package edu.jas.application;
006
007
008import java.io.Serializable;
009
010import edu.jas.structure.RingElem;
011
012
013/**
014 * Serializable subclass to hold pairs of colored polynomials.
015 * @param <C> coefficient type
016 * @author Heinz Kredel
017 */
018public class CPair<C extends RingElem<C>> implements Serializable, Comparable<CPair<C>> {
019
020
021    public final ColorPolynomial<C> pi;
022
023
024    public final ColorPolynomial<C> pj;
025
026
027    public final int i;
028
029
030    public final int j;
031
032
033    protected int n;
034
035
036    protected boolean toZero = false;
037
038
039    protected boolean useCriterion4 = true;
040
041
042    protected boolean useCriterion3 = true;
043
044
045    /**
046     * Pair constructor.
047     * @param a polynomial i.
048     * @param b polynomial j.
049     * @param i first index.
050     * @param j second index.
051     */
052    public CPair(ColorPolynomial<C> a, ColorPolynomial<C> b, int i, int j) {
053        pi = a;
054        pj = b;
055        this.i = i;
056        this.j = j;
057        this.n = 0;
058        toZero = false; // ok
059    }
060
061
062    /**
063     * toString.
064     */
065    @Override
066    public String toString() {
067        return "pair[" + n + "](" + i + "{" + pi.length() + "}," + j + "{" + pj.length()
068                + "}" + ", r0=" + toZero + ", c4=" + useCriterion4 + ", c3="
069                + useCriterion3 + ")";
070    }
071
072
073    /**
074     * Set removed pair number.
075     * @param n number of this pair generated in OrderedPairlist.
076     */
077    public void pairNumber(int n) {
078        this.n = n;
079    }
080
081
082    /**
083     * Get removed pair number.
084     * @return n number of this pair generated in OrderedPairlist.
085     */
086    public int getPairNumber() {
087        return n;
088    }
089
090
091    /**
092     * Set zero reduction. The S-polynomial of this Pair was reduced to zero.
093     */
094    public void setZero() {
095        toZero = true;
096    }
097
098
099    /**
100     * Is reduced to zero.
101     * @return true if the S-polynomial of this Pair was reduced to zero, else
102     *         false.
103     */
104    public boolean isZero() {
105        return toZero;
106    }
107
108
109    /**
110     * equals.
111     * @param ob an Object.
112     * @return true if this is equal to ob, else false.
113     */
114    @Override
115    @SuppressWarnings("unchecked")
116    public boolean equals(Object ob) {
117        CPair<C> cp = null;
118        try {
119            cp = (CPair<C>) ob;
120        } catch ( ClassCastException e) {
121            return false;
122        }
123        if ( cp == null ) {
124            return false;
125        }
126        return 0 == compareTo(cp);
127    }
128
129
130    /**
131     * compareTo used in TreeMap. 
132     * Comparison is based on the number of the pairs.
133     * @param p a Pair.
134     * @return 1 if (this &lt; p), 0 if (this == o), -1 if (this &gt; p).
135     */
136    public int compareTo(CPair<C> p) { // not used at moment
137        int x = p.getPairNumber();
138        if (n > x) {
139            return 1;
140        }
141        if (n < x) {
142            return -1;
143        }
144        return 0;
145    }
146
147
148    /**
149     * Hash code for this pair.
150     * @see java.lang.Object#hashCode()
151     */
152    @Override
153    public int hashCode() {
154        int h;
155        h = getPairNumber();
156        return h;
157    }
158
159
160    /**
161     * Set useCriterion4.
162     * @param c boolean value to set.
163     */
164    public void setUseCriterion4(boolean c) {
165        this.useCriterion4 = c;
166    }
167
168
169    /**
170     * Get useCriterion4.
171     * @return boolean value.
172     */
173    public boolean getUseCriterion4() {
174        return this.useCriterion4;
175    }
176
177
178    /**
179     * Set useCriterion3.
180     * @param c boolean value to set.
181     */
182    public void setUseCriterion3(boolean c) {
183        this.useCriterion3 = c;
184    }
185
186
187    /**
188     * Get useCriterion3.
189     * @return boolean value.
190     */
191    public boolean getUseCriterion3() {
192        return this.useCriterion3;
193    }
194
195}