File: binarySearch.java

package info (click to toggle)
mauve 20120103-1
  • links: PTS, VCS
  • area: main
  • in suites: wheezy
  • size: 28,504 kB
  • sloc: java: 250,155; sh: 2,834; xml: 208; makefile: 66
file content (226 lines) | stat: -rw-r--r-- 7,276 bytes parent folder | download | duplicates (5)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
// Tags: JDK1.2

// Copyright (C) 2004 David Gilbert <david.gilbert@object-refinery.com>

// This file is part of Mauve.

// Mauve is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.

// Mauve is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Mauve; see the file COPYING.  If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.  */

package gnu.testlet.java.util.Collections;

import gnu.testlet.TestHarness;
import gnu.testlet.Testlet;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
import java.util.Vector;

public class binarySearch implements Testlet
{

  public void test(TestHarness harness) 
  {
    // run tests on ArrayList
    harness.checkPoint("ArrayList");
    genericTest(new ArrayList(), harness);
    
    // run tests on LinkedList
    harness.checkPoint("LinkedList");
    genericTest(new LinkedList(), harness);
    
    // run tests on Vector
    harness.checkPoint("Vector");
    genericTest(new Vector(), harness);
    
    // test for a known bug (10447)
    harness.checkPoint("10447");
    testBug10447(harness);

    // comparison order
    harness.checkPoint("Compare Order");
    testCompareOrder(new ArrayList(), harness);
    testCompareOrder(new LinkedList(), harness);
  }

  private void testCompareOrder(List list, TestHarness harness)
  {
    final boolean[] result = new boolean[] { false, false };
    list.add(new Comparable() {
        public int compareTo(Object obj) {
            result[0] = true;
            return -1;
        }
    });
    Collections.binarySearch(list, new Comparable() {
        public int compareTo(Object obj) {
            result[1] = true;
            return -1;
        }
    });
    harness.check(result[0] && !result[1]);

    final Object obj1 = new Object();
    final Object obj2 = new Object();
    list.clear();
    list.add(obj1);
    result[0] = false;
    Collections.binarySearch(list, obj2, new Comparator() {
        public int compare(Object o1, Object o2) {
           result[0] = (o1 == obj1 && o2 == obj2);
           return -1;
        }
    });
    harness.check(result[0]);
  }
  
  private void genericTest(List list, TestHarness harness) 
  {
    // search an empty list...
    list.clear();
    int index = Collections.binarySearch(list, "A");
    harness.check(index, -1);
    
    // search a list with one item...
    list.add("B");
    index = Collections.binarySearch(list, "B");
    harness.check(index, 0);
    index = Collections.binarySearch(list, "A");  // item that would go before "B"
    harness.check(index, -1);
    index = Collections.binarySearch(list, "C");  // item that would go after "B"
    harness.check(index, -2);
    
    // search a list with two items...
    list.add("D");
    index = Collections.binarySearch(list, "A");
    harness.check(index, -1);
    index = Collections.binarySearch(list, "B");
    harness.check(index, 0);
    index = Collections.binarySearch(list, "C");
    harness.check(index, -2);
    index = Collections.binarySearch(list, "D");  
    harness.check(index, 1);
    index = Collections.binarySearch(list, "E");  
    harness.check(index, -3);
    
    // search a list with three items...
    list.add("F");
    index = Collections.binarySearch(list, "A");
    harness.check(index, -1);
    index = Collections.binarySearch(list, "B");
    harness.check(index, 0);
    index = Collections.binarySearch(list, "C");
    harness.check(index, -2);
    index = Collections.binarySearch(list, "D");  
    harness.check(index, 1);
    index = Collections.binarySearch(list, "E");  
    harness.check(index, -3);
    index = Collections.binarySearch(list, "F");  
    harness.check(index, 2);
    index = Collections.binarySearch(list, "G");  
    harness.check(index, -4);
    
    // search some larger lists
    fillList(list, 1024);
    index = Collections.binarySearch(list, "00000");  
    harness.check(index, 0);
    index = Collections.binarySearch(list, "00123");  
    harness.check(index, 123);
    index = Collections.binarySearch(list, "00511");  
    harness.check(index, 511);
    index = Collections.binarySearch(list, "00512");  
    harness.check(index, 512);
    index = Collections.binarySearch(list, "00513");  
    harness.check(index, 513);
    index = Collections.binarySearch(list, "00789");  
    harness.check(index, 789);
    index = Collections.binarySearch(list, "01023");  
    harness.check(index, 1023);
    index = Collections.binarySearch(list, "01024");  
    harness.check(index, -1025);

    fillList(list, 12345);
    index = Collections.binarySearch(list, "00000");  
    harness.check(index, 0);
    index = Collections.binarySearch(list, "00123");  
    harness.check(index, 123);
    index = Collections.binarySearch(list, "00511");  
    harness.check(index, 511);
    index = Collections.binarySearch(list, "00512");  
    harness.check(index, 512);
    index = Collections.binarySearch(list, "00513");  
    harness.check(index, 513);
    index = Collections.binarySearch(list, "00789");  
    harness.check(index, 789);
    index = Collections.binarySearch(list, "01023");  
    harness.check(index, 1023);
    index = Collections.binarySearch(list, "12345");  
    harness.check(index, -12346);

  }

  private void fillList(List list, int itemCount) 
  {
    list.clear();
    for (int i = 0; i < itemCount; i++)
    {
      String s = String.valueOf(i);
      list.add("00000".substring(s.length()) + s);
    }
  }
  
  /**
   * A test for bug report 10447.
   * 
   * @param harness  the test harness.
   */
  private void testBug10447(TestHarness harness) 
  {
    List list = new LinkedList();
    list.add("A"); list.add("B"); list.add("C"); list.add("D"); 
    list.add("E"); list.add("F"); list.add("G"); list.add("H"); 
    list.add("I"); list.add("J"); list.add("K"); list.add("L"); 
    list.add("M"); list.add("N"); list.add("O"); list.add("P"); 
    
    // this works
    int i = Collections.binarySearch(list, "E");
    harness.check(i, 4);
    
    // this doesn't (bug seems to need at least 17 items to trigger)    
    list.add("Q"); 
    i = Collections.binarySearch(list, "E");
    harness.check(i, 4);
      
    // but all is fine for ArrayList
    List list2 = new ArrayList();
    list2.add("A"); list2.add("B"); list2.add("C"); list2.add("D"); 
    list2.add("E"); list2.add("F"); list2.add("G"); list2.add("H"); 
    list2.add("I"); list2.add("J"); list2.add("K"); list2.add("L"); 
    list2.add("M"); list2.add("N"); list2.add("O"); list2.add("P"); 
    
    // this works
    i = Collections.binarySearch(list2, "E");
    harness.check(i, 4);
    
    // and this does too   
    list2.add("Q"); 
    i = Collections.binarySearch(list2, "E");
    harness.check(i, 4);
  }
  
}