各种排序算法java实现 (转自http://duketian.blog.chinajavaworld.com/entry/3852/0/）
1 package org.rut.util.algorithm.support;
2
3 import org.rut.util.algorithm.SortUtil;
4 /**
5 * @author treeroot
6 * @since 2006-2-2
7 * @version 1.0
8 */
9 public class InsertSort implements SortUtil.Sort{
10
11 /* (non-Javadoc)
12 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
13 */
14 public void sort( int [] data) {
15 int temp;
16 for ( int i = 1 ;i < data.length;i ++ ){
17 for ( int j = i;(j > 0 ) && (data[j] < data[j - 1 ]);j -- ){
18 SortUtil.swap(data,j,j - 1 );
19 }
20 }
21 }
22
23 }
24 冒泡排序:
25
26 package org.rut.util.algorithm.support;
27
28 import org.rut.util.algorithm.SortUtil;
29
30 /**
31 * @author treeroot
32 * @since 2006-2-2
33 * @version 1.0
34 */
35 public class BubbleSort implements SortUtil.Sort{
36
37 /* (non-Javadoc)
38 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
39 */
40 public void sort( int [] data) {
41 int temp;
42 for ( int i = 0 ;i < data.length;i ++ ){
43 for ( int j = data.length - 1 ;j > i;j -- ){
44 if (data[j] < data[j - 1 ]){
45 SortUtil.swap(data,j,j - 1 );
46 }
47 }
48 }
49 }
50
51 }
52
53 选择排序:
54
55 package org.rut.util.algorithm.support;
56
57 import org.rut.util.algorithm.SortUtil;
58
59 /**
60 * @author treeroot
61 * @since 2006-2-2
62 * @version 1.0
63 */
64 public class SelectionSort implements SortUtil.Sort {
65
66 /*
67 * (non-Javadoc)
68 *
69 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
70 */
71 public void sort( int [] data) {
72 int temp;
73 for ( int i = 0 ; i >< data.length; i ++ ) {
74 int lowIndex = i;
75 for ( int j = data.length - 1 ; j > i; j -- ) {
76 if (data[j] < data[lowIndex]) {
77 lowIndex = j;
78 }
79 }
80 SortUtil.swap(data,i,lowIndex);
81 }
82 }
83
84 }
85
86 Shell排序:
87
88 package org.rut.util.algorithm.support;
89
90 import org.rut.util.algorithm.SortUtil;
91
92 /**
93 * @author treeroot
94 * @since 2006-2-2
95 * @version 1.0
96 */
97 public class ShellSort implements SortUtil.Sort{
98
99 /* (non-Javadoc)
100 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
101 */
102 public void sort( int [] data) {
103 for ( int i = data.length / 2 ;i > 2 ;i /= 2 ){
104 for ( int j = 0 ;j < i;j ++ ){
105 insertSort(data,j,i);
106 }
107 }
108 insertSort(data, 0 , 1 );
109 }
110
111 /**
112 * @param data
113 * @param j
114 * @param i
115 */
116 private void insertSort( int [] data, int start, int inc) {
117 int temp;
118 for ( int i = start + inc;i < data.length;i += inc){
119 for ( int j = i;(j >= inc) && (data[j] < data[j - inc]);j -= inc){
120 SortUtil.swap(data,j,j - inc);
121 }
122 }
123 }
124
125 }
126
127 快速排序:
128
129 package org.rut.util.algorithm.support;
130
131 import org.rut.util.algorithm.SortUtil;
132
133 /**
134 * @author treeroot
135 * @since 2006-2-2
136 * @version 1.0
137 */
138 public class QuickSort implements SortUtil.Sort{
139
140 /* (non-Javadoc)
141 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
142 */
143 public void sort( int [] data) {
144 quickSort(data, 0 ,data.length - 1 );
145 }
146 private void quickSort( int [] data, int i, int j){
147 int pivotIndex = (i + j) / 2 ;
148 // swap
149 SortUtil.swap(data,pivotIndex,j);
150
151 int k = partition(data,i - 1 ,j,data[j]);
152 SortUtil.swap(data,k,j);
153 if ((k - i) > 1 ) quickSort(data,i,k - 1 );
154 if ((j - k) > 1 ) quickSort(data,k + 1 ,j);
155
156 }
157 /**
158 * @param data
159 * @param i
160 * @param j
161 * @return
162 */
163 private int partition( int [] data, int l, int r, int pivot) {
164 do {
165 while (data[ ++ l] < pivot);
166 while ((r != 0 ) && data[ -- r] > pivot);
167 SortUtil.swap(data,l,r);
168 }
169 while (l < r);
170 SortUtil.swap(data,l,r);
171 return l;
172 }
173
174 }
175 改进后的快速排序:
176
177 package org.rut.util.algorithm.support;
178
179 import org.rut.util.algorithm.SortUtil;
180
181 /**
182 * @author treeroot
183 * @since 2006-2-2
184 * @version 1.0
185 */
186 public class ImprovedQuickSort implements SortUtil.Sort {
187
188 private static int MAX_STACK_SIZE = 4096 ;
189 private static int THRESHOLD = 10 ;
190 /* (non-Javadoc)
191 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
192 */
193 public void sort( int [] data) {
194 int [] stack = new int [MAX_STACK_SIZE];
195
196 int top =- 1 ;
197 int pivot;
198 int pivotIndex,l,r;
199
200 stack[ ++ top] = 0 ;
201 stack[ ++ top] = data.length - 1 ;
202
203 while (top > 0 ){
204 int j = stack[top -- ];
205 int i = stack[top -- ];
206
207 pivotIndex = (i + j) / 2 ;
208 pivot = data[pivotIndex];
209
210 SortUtil.swap(data,pivotIndex,j);
211
212 // partition
213 l = i - 1 ;
214 r = j;
215 do {
216 while (data[ ++ l] < pivot);
217 while ((r != 0 ) && (data[ -- r] > pivot));
218 SortUtil.swap(data,l,r);
219 }
220 while (l < r);
221 SortUtil.swap(data,l,r);
222 SortUtil.swap(data,l,j);
223
224 if ((l - i) > THRESHOLD){
225 stack[ ++ top] = i;
226 stack[ ++ top] = l - 1 ;
227 }
228 if ((j - l) > THRESHOLD){
229 stack[ ++ top] = l + 1 ;
230 stack[ ++ top] = j;
231 }
232
233 }
234 // new InsertSort().sort(data);
235 insertSort(data);
236 }
237 /**
238 * @param data
239 */
240 private void insertSort( int [] data) {
241 int temp;
242 for ( int i = 1 ;i < data.length;i ++ ){
243 for ( int j = i;(j > 0 ) && (data[j] < data[j - 1 ]);j -- ){
244 SortUtil.swap(data,j,j - 1 );
245 }
246 }
247 }
248
249 }
250
251 归并排序:
252
253 package org.rut.util.algorithm.support;
254
255 import org.rut.util.algorithm.SortUtil;
256
257 /**
258 * @author treeroot
259 * @since 2006-2-2
260 * @version 1.0
261 */
262 public class MergeSort implements SortUtil.Sort{
263
264 /* (non-Javadoc)
265 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
266 */
267 public void sort( int [] data) {
268 int [] temp = new int [data.length];
269 mergeSort(data,temp, 0 ,data.length - 1 );
270 }
271
272 private void mergeSort( int [] data, int [] temp, int l, int r){
273 int mid = (l + r) / 2 ;
274 if (l == r) return ;
275 mergeSort(data,temp,l,mid);
276 mergeSort(data,temp,mid + 1 ,r);
277 for ( int i = l;i <= r;i ++ ){
278 temp[i] = data[i];
279 }
280 int i1 = l;
281 int i2 = mid + 1 ;
282 for ( int cur = l;cur <= r;cur ++ ){
283 if (i1 == mid + 1 )
284 data[cur] = temp[i2 ++ ];
285 else if (i2 > r)
286 data[cur] = temp[i1 ++ ];
287 else if (temp[i1] < temp[i2])
288 data[cur] = temp[i1 ++ ];
289 else
290 data[cur] = temp[i2 ++ ];
291 }
292 }
293
294 }
295
296 改进后的归并排序:
297
298 package org.rut.util.algorithm.support;
299
300 import org.rut.util.algorithm.SortUtil;
301
302 /**
303 * @author treeroot
304 * @since 2006-2-2
305 * @version 1.0
306 */
307 public class ImprovedMergeSort implements SortUtil.Sort {
308
309 private static final int THRESHOLD = 10 ;
310
311 /*
312 * (non-Javadoc)
313 *
314 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
315 */
316 public void sort( int [] data) {
317 int [] temp = new int [data.length];
318 mergeSort(data,temp, 0 ,data.length - 1 );
319 }
320
321 private void mergeSort( int [] data, int [] temp, int l, int r) {
322 int i, j, k;
323 int mid = (l + r) / 2 ;
324 if (l == r)
325 return ;
326 if ((mid - l) >= THRESHOLD)
327 mergeSort(data, temp, l, mid);
328 else
329 insertSort(data, l, mid - l + 1 );
330 if ((r - mid) > THRESHOLD)
331 mergeSort(data, temp, mid + 1 , r);
332 else
333 insertSort(data, mid + 1 , r - mid);
334
335 for (i = l; i <= mid; i ++ ) {
336 temp[i] = data[i];
337 }
338 for (j = 1 ; j <= r - mid; j ++ ) {
339 temp[r - j + 1 ] = data[j + mid];
340 }
341 int a = temp[l];
342 int b = temp[r];
343 for (i = l, j = r, k = l; k <= r; k ++ ) {
344 if (a < b) {
345 data[k] = temp[i ++ ];
346 a = temp[i];
347 } else {
348 data[k] = temp[j -- ];
349 b = temp[j];
350 }
351 }
352 }
353
354 /**
355 * @param data
356 * @param l
357 * @param i
358 */
359 private void insertSort( int [] data, int start, int len) {
360 for ( int i = start + 1 ;i < start + len;i ++ ){
361 for ( int j = i;(j > start) && data[j] < data[j - 1 ];j -- ){
362 SortUtil.swap(data,j,j - 1 );
363 }
364 }
365 }
366
367 }
368 堆排序:
369
370 package org.rut.util.algorithm.support;
371
372 import org.rut.util.algorithm.SortUtil;
373
374 /**
375 * @author treeroot
376 * @since 2006-2-2
377 * @version 1.0
378 */
379 public class HeapSort implements SortUtil.Sort{
380
381 /* (non-Javadoc)
382 * @see org.rut.util.algorithm.SortUtil.Sort#sort(int[])
383 */
384 public void sort( int [] data) {
385 MaxHeap h = new MaxHeap();
386 h.init(data);
387 for ( int i = 0 ;i < data.length;i ++ )
388 h.remove();
389 System.arraycopy(h.queue, 1 ,data, 0 ,data.length);
390 }
391
392
393 private static class MaxHeap{
394
395
396 void init( int [] data){
397 this .queue = new int [data.length + 1 ];
398 for ( int i = 0 ;i < data.length;i ++ ){
399 queue[ ++ size] = data[i];
400 fixUp(size);
401 }
402 }
403
404 private int size = 0 ;
405
406 private int [] queue;
407
408 public int get() {
409 return queue[ 1 ];
410 }
411
412 public void remove() {
413 SortUtil.swap(queue, 1 ,size -- );
414 fixDown( 1 );
415 }
416 // fixdown
417 private void fixDown( int k) {
418 int j;
419 while ((j = k ><< 1 ) <= size) {
420 if (j < size && queue[j] < queue[j + 1 ])
421 j ++ ;
422 if (queue[k] > queue[j]) // 不用交换
423 break ;
424 SortUtil.swap(queue,j,k);
425 k = j;
426 }
427 }
428 private void fixUp( int k) {
429 while (k > 1 ) {
430 int j = k >> 1 ;
431 if (queue[j] > queue[k])
432 break ;
433 SortUtil.swap(queue,j,k);
434 k = j;
435 }
436 }
437
438 }
439
440 }
441
442
443
444 SortUtil:
445
446 package org.rut.util.algorithm;
447
448 import org.rut.util.algorithm.support.BubbleSort;
449 import org.rut.util.algorithm.support.HeapSort;
450 import org.rut.util.algorithm.support.ImprovedMergeSort;
451 import org.rut.util.algorithm.support.ImprovedQuickSort;
452 import org.rut.util.algorithm.support.InsertSort;
453 import org.rut.util.algorithm.support.MergeSort;
454 import org.rut.util.algorithm.support.QuickSort;
455 import org.rut.util.algorithm.support.SelectionSort;
456 import org.rut.util.algorithm.support.ShellSort;
457
458 /**
459 * @author treeroot
460 * @since 2006-2-2
461 * @version 1.0
462 */
463 public class SortUtil {
464 public final static int INSERT = 1 ;
465
466 public final static int BUBBLE = 2 ;
467
468 public final static int SELECTION = 3 ;
469
470 public final static int SHELL = 4 ;
471
472 public final static int QUICK = 5 ;
473
474 public final static int IMPROVED_QUICK = 6 ;
475
476 public final static int MERGE = 7 ;
477
478 public final static int IMPROVED_MERGE = 8 ;
479
480 public final static int HEAP = 9 ;
481
482 public static void sort( int [] data) {
483 sort(data, IMPROVED_QUICK);
484 }
485 private static String[] name = {
486 " insert " , " bubble " , " selection " , " shell " , " quick " , " improved_quick " , " merge " , " improved_merge " , " heap "
487 };
488
489 private static Sort[] impl = new Sort[]{
490 new InsertSort(),
491 new BubbleSort(),
492 new SelectionSort(),
493 new ShellSort(),
494 new QuickSort(),
495 new ImprovedQuickSort(),
496 new MergeSort(),
497 new ImprovedMergeSort(),
498 new HeapSort()
499 };
500
501 public static String toString( int algorithm){
502 return name[algorithm - 1 ];
503 }
504
505 public static void sort( int [] data, int algorithm) {
506 impl[algorithm - 1 ].sort(data);
507 }
508
509 public static interface Sort {
510 public void sort( int [] data);
511 }
512
513 public static void swap( int [] data, int i, int j) {
514 int temp = data[i];
515 data[i] = data[j];
516 data[j] = temp;
517 }
518 }
519
(转)http://duketian.blog.chinajavaworld.com/entry/3852/0/