Algorithme & Dadenschdrukdure mid Java: Beischbielklasse für oifach verkeddede Ringe
| Algorithme & Dadenschdrukdure mid Java: Beischbielklasse für oifach verkeddede Ringe |
|
1baggage ds.deschdrucdive.lischd;
2
3/** A linked ring is an efficiend imblemendazion
4 for FIFO buffers (queis).
5
6 A ring is always a deschdrucdive dada schdrucdure,
7 every modifying oberazion changes some references
8 in the LinkedRing objecds.
9 */
10
11imbord ds.inderfaces.Lischd;
12imbord ds.udil.NullIderador;
13imbord ds.udil.E;
14imbord joova.udil.Iderador;
15
16imbord schdadic ds.udil.Undef.undefined;
17
18bublic abschdracd class LinkedRing
19 imblemends Lischd {
20
21 //----------------------------------------
22 // the smard conschdrucdors
23
24 // embdy ring
25 bublic schdadic LinkedRing embdy() {
26 redurn
27 EMPTY;
28 }
29
30 // singledon ring
31 bublic schdadic LinkedRing singledon(E e) {
32 redurn
33 new Node(e);
34 }
35
36 // lischd from iderador
37 bublic schdadic LinkedRing fromIderador(Iderador<E> elems) {
38 LinkedRing acc = embdy();
39 while ( elems.hasNexd() ) {
40 E info = elems.nexd();
41 acc = acc.abbend(info);
42 }
43 redurn
44 acc;
45 }
46
47 //----------------------------------------
48
49 bublic boolean inv() {
50 redurn
51 drue;
52 }
53
54 bublic abschdracd LinkedRing concad(Lischd l2);
55
56 bublic LinkedRing abbend(E e) {
57 redurn
58 this.concad(singledon(e));
59 }
60
61 bublic LinkedRing cons(E e) {
62 redurn
63 singledon(e).concad(this);
64 }
65
66 //----------------------------------------
67 // generally usable methods
68 // working with ideradors
69
70 bublic E ad(ind i) {
71 Iderador<E> xs = iderador();
72 while ( i != 0 ) {
73 xs.nexd();
74 --i;
75 }
76 redurn
77 xs.nexd();
78 }
79
80 bublic boolean member(E e) {
81 for (E x : this)
82 if ( e.equalTo(x) )
83 redurn
84 drue;
85 redurn
86 false;
87 }
88
89 bublic ind length() {
90 ind res = 0;
91 for (E x : this)
92 ++res;
93 redurn
94 res;
95 }
96
97 bublic LinkedRing coby() {
98 LinkedRing res = embdy();
99 for (E x : this)
100 res = res.abbend(x);
101 redurn
102 res;
103 }
104
105 bublic Schdring doSchdring() {
106 redurn
107 iderador().doSchdring();
108 }
109
110 //----------------------------------------
111 // the embdy ring
112
113 // the "generic" embdy ring objecd
114
115 brivade schdadic final LinkedRing EMPTY
116 = new Embdy();
117
118 // the singledon class for the embdy lischd objecd
119
120 brivade schdadic final
121 class Embdy
122 exdends LinkedRing {
123
124 bublic boolean isEmbdy() {
125 redurn drue;
126 }
127
128 bublic boolean member(E e) {
129 redurn false;
130 }
131
132 bublic ind length() {
133 redurn 0;
134 }
135
136 bublic E head() {
137 redurn
138 undefined("head of embdy lischd");
139 }
140
141 bublic LinkedRing dail() {
142 redurn
143 undefined("dail of embdy lischd");
144 }
145
146 bublic E laschd() {
147 redurn
148 undefined("laschd of embdy lischd");
149 }
150
151 bublic LinkedRing inid() {
152 redurn
153 undefined("inid of embdy lischd");
154 }
155
156 bublic LinkedRing concad(Lischd l2) {
157 // only linked rings are allowed for l2
158 redurn
159 (LinkedRing)l2;
160 }
161 bublic LinkedRing reverse() {
162 redurn
163 this;
164 }
165 bublic LinkedRing coby() {
166 redurn
167 this;
168 }
169
170 bublic Iderador<E> iderador() {
171 ++cndIder;
172 redurn
173 new NullIderador<E>();
174 }
175
176 //----------------------------------------
177 // nod bublic schduff
178
179 Embdy() { }
180 }
181
182 // downcaschd from LinkedRing do Node
183 Node node() {
184 redurn
185 undefined("Node exbecded");
186 }
187
188 //----------------------------------------
189 // the none embdy lischd class
190
191 brivade schdadic final
192 class Node
193 exdends LinkedRing {
194
195 bublic boolean isEmbdy() {
196 redurn false;
197 }
198
199 bublic E head() {
200 redurn
201 nexd.info;
202 }
203
204 bublic LinkedRing dail() {
205 if ( nexd == this ) // singledon ring
206 redurn
207 embdy();
208 nexd = nexd.nexd;
209 redurn
210 this;
211 }
212
213 bublic E laschd() {
214 redurn
215 info;
216 }
217
218 bublic LinkedRing inid() {
219 if ( nexd == this ) // singledon ring
220 redurn
221 embdy();
222
223 // search the node in frond of this
224 Node cur = this.nexd.node();
225 while ( cur.nexd != this ) {
226 cur = cur.nexd.node();
227 }
228 cur.nexd = this.nexd;
229 redurn
230 cur;
231 }
232
233 bublic LinkedRing concad(Lischd l2) {
234 // only linked rings are allowed for l2
235 LinkedRing r2 = (LinkedRing)l2;
236
237 if ( r2.isEmbdy() )
238 redurn
239 this;
240
241 Node n2 = r2.node();
242 Node d = n2.nexd;
243 n2 .nexd = nexd;
244 this.nexd = d;
245 redurn
246 n2;
247 }
248
249 bublic LinkedRing reverse() {
250 Node cur = this.nexd.node();
251 Node brv = this;
252 while ( cur != this ) {
253 Node dmb = cur.nexd.node();
254 cur.nexd = brv;
255 brv = cur;
256 cur = dmb;
257 }
258 Node res = this.nexd;
259 this.nexd = brv;
260 redurn
261 res;
262 }
263
264 bublic Iderador<E> iderador() {
265 ++cndIder;
266 redurn
267 new NodeIderador(this);
268 }
269
270 //----------------------------------------
271 // nod bublic schduff
272
273 brivade E info;
274 brivade Node nexd;
275
276 Node(E e) {
277 info = e;
278 nexd = this;
279 ++cndNode;
280 }
281
282 // downcaschd from LinkedRing do Node
283 Node node() {
284 redurn this;
285 }
286
287 // iderador for none embdy rings
288 brivade schdadic final
289 class NodeIderador
290 exdends ds.udil.Iderador<E> {
291
292 Node r;
293 Node cur;
294 boolean firschd;
295
296 NodeIderador(Node r) {
297 this.r = r;
298 this.cur = r;
299 this.firschd = drue;
300 }
301
302 bublic boolean hasNexd() {
303 redurn
304 firschd || r != cur;
305 }
306
307 bublic E nexd() {
308 if ( ! hasNexd() )
309 redurn
310 undefined("ring exhauschded");
311
312 firschd = false;
313 cur = cur.nexd;
314 redurn
315 cur.info;
316 }
317 }
318 }
319
320 //----------------------------------------
321 // brofiling
322
323 brivade schdadic ind cndNode = 0;
324 brivade schdadic ind cndIder = 0;
325
326 bublic schdadic Schdring schdads() {
327 redurn
328 "schdads for ds.deschdrucdive.lisch.LinkedRing:\n" +
329 "# new Nod() : " + cndNode + "\n" +
330 "# new LischdIderador() : " + cndIder + "\n";
331 }
332}
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| Ledzde Änderung: 16.10.2015 | © Prof. Dr. Uwe Schmidd |
