001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
091
092
093
094
095
096
097
098
099
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
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
package algs13;
import java.text.DecimalFormat;
import stdlib.*;

/* 
 * Complete the methods below.
 * See the tests in main for examples of what each function should do.
 * 
 * deleteFirst should modify the list.
 * None of the other methods should modify the list.
 * 
 * You may not add any fields to the node or list classes.
 * You may not add any methods to the node class.
 * You may not change method or field names.
 * You may not create any new node objects or other objects.
 * For example, you cannot create a new Stack or ArrayList.
 * 
 * Each function must be independent: you cannot call one solution function from the other.  
 * You MAY add private methods to the list class 
 * (helper functions for recursion, if you chose to use it).
 */
public class MyLinked0 {
  static class Node {
    public Node (double item, Node next) { this.item = item; this.next = next; }
    public double item;
    public Node next;
  }
  Node first;

  // Return the size of the list
  // See the tests for more...
  public int size () {
    return StdRandom.uniform (100); //TODO
  }

  // Return the sum of the positive elements of the list
  // See the tests for more...
  public double sumPositiveElements () {
    return StdRandom.random (); //TODO
  }
  
  // Return the length of the common prefix for this and that
  // See the tests for more...
  public int lengthOfCommonPrefix (MyLinked0 that) {
    return StdRandom.uniform (100); //TODO
  }
  
  // Return true if the elements are strictly increasing
  // See the tests for more...
  public boolean isIncreasing () {
    return StdRandom.bernoulli(); //TODO
  }
  
  // Return true if the even indexed elements are strictly increasing
  // See the tests for more...
  public boolean evenIndicesIncreasing () {
    return StdRandom.bernoulli(); //TODO
  }
  
  // Delete the first element from this list, if it exists
  // Do nothing if the list is empty
  // This is similar to Stack.pop
  public void deleteFirst () {
    // TODO
  }

  public static void main (String args[]) {
    //mainDebug ();
    mainRunTests ();
  }
  private static void mainDebug () {
    // Use this for debugging!
    // Uncomment the call in main to use this.
    // Add the names of helper functions if you use them.
    Trace.drawStepsOfMethod ("size");
    Trace.drawStepsOfMethod ("sumPositiveElements");
    Trace.drawStepsOfMethod ("lengthOfCommonPrefix");
    Trace.drawStepsOfMethod ("isIncreasing");
    Trace.drawStepsOfMethod ("evenIndicesIncreasing");
    Trace.drawStepsOfMethod ("deleteFirst");
    //Trace.showObjectIdsRedundantly(true);
    Trace.run (); 
    // TODO:  Put the test here you want to debug:
    //testSumPositiveElements (104, "11 -3 -4 21 31 41 -1");
    //testLengthOfCommonPrefix (3, "11 21 31 41 41", "11 21 31 5 41");
    //testIsIncreasing(true,  "11 21 31 41");
    //testEvenIndicesIncreasing(true,  "11 0 21 11 31 0 41");
    //testDeleteFirst ("21 31", "11 21 31");  
    StdOut.println ("Finished tests");
  }
  private static void mainRunTests () {
    testSize (2, "11 21");  
    testSize (4, "11 -21.2 31 41");
    testSize (1, "11");
    testSize (0, ""); 
    
    testSumPositiveElements (104, "11 -3 -4 21 31 41 -1");
    testSumPositiveElements (104, "11 -3 -4 21 31 -1 41");
    testSumPositiveElements (0, "-11.2");
    testSumPositiveElements (52, "11 -21 -31 41");
    testSumPositiveElements (0, "");
    testSumPositiveElements (11, "11");
    
        testLengthOfCommonPrefix (3, "11 21 31 41 41", "11 21 31 5 41");
        testLengthOfCommonPrefix (3, "11 21 31 41 41 51", "11 21 31 5 41 51");
        testLengthOfCommonPrefix (3, "11 21 31 41 5", "11 21 31 5 41");
    testLengthOfCommonPrefix (3, "11 21 31 5 41", "11 21 31 41 5");
    testLengthOfCommonPrefix (2, "11 21 31 41 5", "11 21 5 31 41");
    testLengthOfCommonPrefix (2, "11 21 5 31 41", "11 21 31 41 5");
    testLengthOfCommonPrefix (1, "11 21 31 41 5", "11 5 21 31 41");
    testLengthOfCommonPrefix (1, "11 5 21 31 41", "11 21 31 41");
    testLengthOfCommonPrefix (0, "11 21 31 41", "5 11 21 31 41");
    testLengthOfCommonPrefix (0, "5 11 21 31 41", "11 21 31 41");
    testLengthOfCommonPrefix (3, "11 21 31 41", "11 21 31 5 41");
    testLengthOfCommonPrefix (3, "11 21 31", "11 21 31");
    testLengthOfCommonPrefix (3, "11 21 31", "11 21 31 41");
    testLengthOfCommonPrefix (2, "11 21 31 41", "11 21");
    testLengthOfCommonPrefix (1, "11", "11 21 31 41");
    testLengthOfCommonPrefix (1, "11", "11");
    testLengthOfCommonPrefix (0, "11", "5");
    testLengthOfCommonPrefix (0, "11 21 31 41", "");
    testLengthOfCommonPrefix (0, "", "11 21 31 41");
    testLengthOfCommonPrefix (0, "", "");

    testIsIncreasing(true,  "11 21 31 41");
    testIsIncreasing(true,  "11 21 31 41 51");
    testIsIncreasing(false, "11 21 21 31 41 51");
    testIsIncreasing(false, "11 21 5 31 41 51");
    testIsIncreasing(false, "11 21 5 31 41 51");
    testIsIncreasing(false, "11 21 31 5 41 51");
    testIsIncreasing(false, "11 21 31 41 5 51");
    testIsIncreasing(false, "11 21 31 41 51 5");
    testIsIncreasing(false, "11 21 5 31 41");
    testIsIncreasing(false, "11 5 21 31 41");
    testIsIncreasing(false, "11 21 31 5 41");
    testIsIncreasing(false, "11 21 31 41 5");
    testIsIncreasing(false, "11 5");
    testIsIncreasing(true,  "11 21");
    testIsIncreasing(true,  "11");
    testIsIncreasing(true,  "");
    
    testEvenIndicesIncreasing(true,  "11 0 21 11 31 0 41 0");
    testEvenIndicesIncreasing(true,  "11 0 21 11 31 0 41");
    testEvenIndicesIncreasing(true,  "-41 0 -31 11 -21 0 -11");
    testEvenIndicesIncreasing(false, "11 0 21 0 5 11 31 0 41");
    testEvenIndicesIncreasing(false, "11 0 21 0 21 11 31 0 41");
    testEvenIndicesIncreasing(false, "-41 0 -31 11 21 0 -11");
    testEvenIndicesIncreasing(true,  "-21 -11 31");
    testEvenIndicesIncreasing(false, "11 -3 -4 21 31 41 -1");   
    testEvenIndicesIncreasing(false, "11 -21 -31 41");    
    testEvenIndicesIncreasing(false, "11 -3 -4 21 31 -1 41");   
    testEvenIndicesIncreasing(true,  "11 1 21 -2 31 -3");
    testEvenIndicesIncreasing(false, "11 1 21 -2 31 -3 5");
    testEvenIndicesIncreasing(true,  "11 1 21 -2 31");
    testEvenIndicesIncreasing(false, "11 1 21 -2 5 -3");
    testEvenIndicesIncreasing(true,  "11 1 21 -2");
    testEvenIndicesIncreasing(true,  "11 1 21");
    testEvenIndicesIncreasing(true,  "11 1");
    testEvenIndicesIncreasing(true,  "11");
    testEvenIndicesIncreasing(true,  "-11");
    testEvenIndicesIncreasing(true,  "");

    testDeleteFirst ("21 31", "11 21 31");  
    testDeleteFirst ("21 11", "31 21 11");
    testDeleteFirst ("21", "11 21");  
    testDeleteFirst ("", "11");
    testDeleteFirst ("", "");
    
    StdOut.println ("Finished tests");
  }
  

  /* ToString method to print */
  public String toString () { 
    // Use DecimalFormat #.### rather than String.format 0.3f to leave off trailing zeroes
    DecimalFormat format = new DecimalFormat ("#.###");
    StringBuilder result = new StringBuilder ("[ ");
    for (Node x = first; x != null; x = x.next) {
      result.append (format.format (x.item));
      result.append (" ");
    }
    result.append ("]");
    return result.toString ();
  }
  public String toStringWithQuadraticPerformance () { 
    // Use DecimalFormat #.### rather than String.format 0.3f to leave off trailing zeroes
    DecimalFormat format = new DecimalFormat ("#.###");
    String result = "";
    for (Node x = first; x != null; x = x.next) {
      result += format.format (x.item);
      result += " ";
    }
    result += "]";
    return result;
  }

  /* Method to create lists */
  public static MyLinked0 from(String s) {
    var result = new MyLinked0 ();
    if ("".equals (s)) return result;
    
    Node first = null;
    String[] nums = s.split (" ");
    for (int i = nums.length-1; i >= 0; i--) {
      try { 
        double num = Double.parseDouble (nums[i]); 
        first = new Node (num, first);      
      } catch (NumberFormatException e) {
        throw new IllegalArgumentException (String.format ("Bad argument \"%s\": could not parse \"%s\" as a double", s, nums[i]));
      }
    }
    result.first = first;
    return result;
  }

  // lots of copy and paste in these test!
  private static void testSize (int expected, String sList) {
    var list = MyLinked0.from (sList);
    String sStart = list.toString ();
    int actual = list.size();
    if (expected != actual) {
      StdOut.format ("Failed %s.size(): Expecting (%d) Actual (%d)\n", sStart, expected, actual);
    }
    String sEnd = list.toString ();
    if (! sStart.equals (sEnd)) {
      StdOut.format ("Failed %s.size(): List changed to %s\n", sStart, sEnd);
    }
  } 
  private static void testSumPositiveElements (double expected, String sList) {
    var list = MyLinked0.from (sList);
    String sStart = list.toString ();
    double actual = list.sumPositiveElements ();
    if (expected != actual) {
      StdOut.format ("Failed %s.sumPositiveElements(): Expecting (%f) Actual (%f)\n", sStart, expected, actual);
    }
    String sEnd = list.toString ();
    if (!sStart.equals (sEnd)) {
      StdOut.format ("Failed %s.sumPositiveElements(): List changed to %s\n", sStart, sEnd);
    }
  }
  private static void testDeleteFirst (String expected, String sList) {
    String sExpected = MyLinked0.from (expected).toString ();
    var list = MyLinked0.from (sList);
    String sStart = list.toString ();
    list.deleteFirst ();
    String sEnd = list.toString ();
    if (! sExpected.equals (sEnd)) {
      StdOut.format ("Failed %s.deleteFirst(): Expecting %s Actual %s\n", sStart, sExpected, sEnd);
    }
  }
  private static void testIsIncreasing(boolean expected, String sList) {
    var list = MyLinked0.from (sList);
    String sStart = list.toString ();
    boolean actual = list.isIncreasing ();
    if (expected != actual) {
      StdOut.format ("Failed %s.isIncreasing(): Expecting (%b) Actual (%b)\n", sStart, expected, actual);
    }
    String sEnd = list.toString ();
    if (!sStart.equals (sEnd)) {
      StdOut.format ("Failed %s.isIncreasing(): List changed to %s\n", sStart, sEnd);
    }
  }
  private static void testEvenIndicesIncreasing(boolean expected, String sList) {
    var list = MyLinked0.from (sList);
    String sStart = list.toString ();
    boolean actual = list.evenIndicesIncreasing ();
    if (expected != actual) {
      StdOut.format ("Failed %s.evenIndicesIncreasing(): Expecting (%b) Actual (%b)\n", sStart, expected, actual);
    }
    String sEnd = list.toString ();
    if (!sStart.equals (sEnd)) {
      StdOut.format ("Failed %s.evenIndicesIncreasing(): List changed to %s\n", sStart, sEnd);
    }
  }
  private static void testLengthOfCommonPrefix(int expected, String sList1, String sList2) {
    var list1 = MyLinked0.from (sList1);
    var list2 = MyLinked0.from (sList2);
    String sStart1 = list1.toString ();
    String sStart2 = list2.toString ();
    int actual = list1.lengthOfCommonPrefix(list2);
    if (expected != actual) {
      StdOut.format ("Failed %s.lengthOfCommonPrefix(%s): Expecting (%d) Actual (%d)\n", sStart1, sStart2, expected, actual);
    }
    String sEnd1 = list1.toString ();
    if (!sStart1.equals (sEnd1)) {
      StdOut.format ("Failed %s.lengthOfCommonPrefix(%s): List changed to %s\n", sStart1, sStart2, sEnd1);
    }
    String sEnd2 = list2.toString ();
    if (!sStart2.equals (sEnd2)) {
      StdOut.format ("Failed %s.lengthOfCommonPrefix(%s): List changed to %s\n", sStart1, sStart2, sEnd2);
    }
  }
}