001 package com.croftsoft.apps.fraction;
002
003 import java.util.Random;
004
005 import com.croftsoft.core.math.MathLib;
006
007 /*********************************************************************
008 * Question data.
009 *
010 * @version
011 * 2002-07-20
012 * @since
013 * 2002-07-20
014 * @author
015 * <a href="https://www.croftsoft.com/">David Wallace Croft</a>
016 *********************************************************************/
017
018 public final class FractionQuestion
019 //////////////////////////////////////////////////////////////////////
020 //////////////////////////////////////////////////////////////////////
021 {
022
023 private final int maxDenominator;
024
025 private final Random random;
026
027 //
028
029 private int firstDenominator;
030
031 private int firstNumerator;
032
033 private int secondDenominator;
034
035 private int secondNumerator;
036
037 private int thirdDenominator;
038
039 private int thirdNumerator;
040
041 //
042
043 private int commonDenominator;
044
045 private int firstAnswerNumerator;
046
047 private int secondAnswerNumerator;
048
049 private int thirdAnswerNumerator;
050
051 //
052
053 private boolean first;
054
055 private boolean second;
056
057 private boolean third;
058
059 private boolean fourth;
060
061 //////////////////////////////////////////////////////////////////////
062 //////////////////////////////////////////////////////////////////////
063
064 public FractionQuestion ( int maxDenominator )
065 //////////////////////////////////////////////////////////////////////
066 {
067 if ( maxDenominator < 1 )
068 {
069 throw new IllegalArgumentException ( "maxDenominator < 1" );
070 }
071
072 this.maxDenominator = maxDenominator;
073
074 this.random = new Random ( );
075
076 reset ( );
077 }
078
079 //////////////////////////////////////////////////////////////////////
080 //////////////////////////////////////////////////////////////////////
081
082 public void reset ( )
083 //////////////////////////////////////////////////////////////////////
084 {
085 first = false;
086
087 second = false;
088
089 third = false;
090
091 fourth = false;
092
093 int gcf;
094
095 while ( true )
096 {
097 firstDenominator = random.nextInt ( maxDenominator ) + 1;
098
099 firstNumerator = random.nextInt ( firstDenominator + 1 );
100
101 if ( firstNumerator == 0 )
102 {
103 continue;
104 }
105 else
106 {
107 gcf = MathLib.greatestCommonFactor (
108 firstDenominator, firstNumerator );
109
110 firstDenominator /= gcf;
111
112 firstNumerator /= gcf;
113 }
114
115 secondDenominator = random.nextInt ( maxDenominator ) + 1;
116
117 secondNumerator = random.nextInt ( secondDenominator + 1 );
118
119 if ( secondNumerator == 0 )
120 {
121 continue;
122 }
123 else
124 {
125 gcf = MathLib.greatestCommonFactor (
126 secondDenominator, secondNumerator );
127
128 secondDenominator /= gcf;
129
130 secondNumerator /= gcf;
131 }
132
133 if ( firstDenominator > secondDenominator )
134 {
135 if ( firstDenominator % secondDenominator == 0 )
136 {
137 commonDenominator = firstDenominator;
138 }
139 else
140 {
141 commonDenominator = firstDenominator * secondDenominator;
142 }
143 }
144 else if ( firstDenominator < secondDenominator )
145 {
146 if ( secondDenominator % firstDenominator == 0 )
147 {
148 commonDenominator = secondDenominator;
149 }
150 else
151 {
152 commonDenominator = firstDenominator * secondDenominator;
153 }
154 }
155 else
156 {
157 continue;
158 }
159
160 if ( commonDenominator > maxDenominator )
161 {
162 continue;
163 }
164
165 firstAnswerNumerator
166 = ( commonDenominator / firstDenominator ) * firstNumerator;
167
168 secondAnswerNumerator
169 = ( commonDenominator / secondDenominator ) * secondNumerator;
170
171 thirdAnswerNumerator = firstAnswerNumerator + secondAnswerNumerator;
172
173 thirdNumerator = thirdAnswerNumerator;
174
175 if ( thirdNumerator == 0 )
176 {
177 thirdDenominator = 1;
178 }
179 else
180 {
181 thirdDenominator = commonDenominator;
182
183 gcf = MathLib.greatestCommonFactor (
184 thirdDenominator, thirdNumerator );
185
186 thirdDenominator /= gcf;
187
188 thirdNumerator /= gcf;
189 }
190
191 if ( ( thirdNumerator <= thirdDenominator )
192 && ( thirdDenominator <= maxDenominator ) )
193 {
194 break;
195 }
196 }
197 }
198
199 //////////////////////////////////////////////////////////////////////
200 //////////////////////////////////////////////////////////////////////
201
202 public int getFirstDenominator ( ) { return firstDenominator; }
203
204 public int getFirstNumerator ( ) { return firstNumerator; }
205
206 public int getSecondDenominator ( ) { return secondDenominator; }
207
208 public int getSecondNumerator ( ) { return secondNumerator; }
209
210 public int getThirdDenominator ( ) { return thirdDenominator; }
211
212 public int getThirdNumerator ( ) { return thirdNumerator; }
213
214 //////////////////////////////////////////////////////////////////////
215 //////////////////////////////////////////////////////////////////////
216
217 public int getCommonDenominator ( ) { return commonDenominator; }
218
219 public int getFirstAnswerNumerator ( )
220 { return firstAnswerNumerator; }
221
222 public int getSecondAnswerNumerator ( )
223 { return secondAnswerNumerator; }
224
225 public int getThirdAnswerNumerator ( )
226 { return thirdAnswerNumerator; }
227
228 //////////////////////////////////////////////////////////////////////
229 //////////////////////////////////////////////////////////////////////
230
231 public boolean getFirst ( ) { return first; }
232
233 public boolean getSecond ( ) { return second; }
234
235 public boolean getThird ( ) { return third; }
236
237 public boolean getFourth ( ) { return fourth; }
238
239 public void setFirst ( boolean first ) { this.first = first; }
240
241 public void setSecond ( boolean second ) { this.second = second; }
242
243 public void setThird ( boolean third ) { this.third = third; }
244
245 public void setFourth ( boolean fourth ) { this.fourth = fourth; }
246
247 //////////////////////////////////////////////////////////////////////
248 //////////////////////////////////////////////////////////////////////
249 }