1 public class FibHeap
2 {
3 private FibNode min;
4
5 private int count;
6
7 private FibNode root;
8
9
10 public FibHeap()
11 {
12 root = new FibNode();
13 root.left = root;
14 root.right = root;
15 }
16
17 /*
18 * 返回最小节点
19 */
20 public FibNode min()
21 {
22 return min;
23 }
24
25 /*
26 * 删除节点
27 */
28 public void delete(FibNode node)
29 {
30 decereaseKey(node, Integer.MIN_VALUE);
31 extractMin();
32 }
33
34 /*
35 * 减小某结点的值
36 */
37 public void decereaseKey(FibNode node, int k)
38 {
39 if (node.key < k) {
40 throw new RuntimeException("new key is greater than current key");
41 }
42
43 node.key = k;
44 FibNode parent = node.parent;
45 if (parent != null && node.key < parent.key) {
46 cut(node, parent);
47 cascadingCut(parent);
48 }
49
50 if (node.key < min.key) min = node;
51 }
52
53 /*
54 * 剔除node节点并执行insertRoot
55 */
56 public void cut(FibNode node, FibNode parent)
57 {
58 node.left.right = node.right;
59 node.right.left = node.left;
60 parent.degree--;
61
62 insertRoot(node);
63 node.parent = null;
64 node.mark = false;
65 }
66
67 /*
68 * ??????
69 */
70 public void cascadingCut(FibNode node)
71 {
72 FibNode parent = node.parent;
73 if (parent != null) {
74 if (!node.mark) {
75 node.mark = true;
76 }
77 else {
78 cut(node, parent);
79 cascadingCut(parent);
80 }
81 }
82 }
83
84 /*
85 * 抽取最小关键子节点
86 */
87 public FibNode extractMin()
88 {
89 FibNode node = min;
90 if (node != null) {
91
92 if (node.degree != 0) {
93 FibNode child = node.child;
94 FibNode next = child;
95
96 do {
97 next.parent = null;
98 next = next.right;
99 }
100 while (child != next);
101
102 node.left.right = child.right;
103 child.right.left = node.left;
104 node.right.left = child;
105 child.right = node.right;
106 }
107 else {
108 node.left.right = node.right;
109 node.right.left = node.left;
110 }
111
112 if (node == node.right) {
113 min = null;
114 }
115 else {
116 min = min.right;
117 consolidate();
118 }
119 count--;
120 }
121 return node;
122 }
123
124 /*
125 * 输出根节点
126 */
127 public void displayRoot()
128 {
129 FibNode node = root.right;
130 while (node != root) {
131 System.out.println(node.key);
132 node = node.right;
133 }
134 }
135
136 /*
137 * 合并
138 */
139 public void consolidate()
140 {
141 FibNode[] array = new FibNode[(int) (Math.log(count) / Math.log(2)) + 1];
142
143 FibNode node = root.right;
144 while (node != root) {
145 FibNode nodex = node;
146 node = node.right;
147 int degree = nodex.degree;
148
149 while (array[degree] != null) {
150 FibNode nodey = array[degree];
151 if (nodex.key > nodey.key) {
152 // swap
153 FibNode temp = nodex;
154 nodex = nodey;
155 nodey = temp;
156 }
157 link(nodey, nodex);
158 array[degree++] = null;
159 }
160 array[degree] = nodex;
161 }
162
163 min = null;
164 for (int i = 0; i < array.length; i++) {
165 if (array[i] != null) {
166 if (min == null || array[i].key < min.key) {
167 min = array[i];
168 }
169 }
170 }
171 }
172
173 /*
174 * 连接节点
175 */
176 public void link(FibNode node, FibNode parent)
177 {
178 node.left.right = node.right;
179 node.right.left = node.left;
180 node.parent = parent;
181
182 if (parent.degree == 0) {
183 parent.child = node;
184 node.left = node;
185 node.right = node;
186 }
187 else {
188 node.left = parent.child.left;
189 parent.child.left.right = node;
190 node.right = parent.child;
191 parent.child.left = node;
192 }
193
194 parent.degree++;
195 node.mark = false;
196 }
197
198 /*
199 * 插入节点
200 */
201 public void insert(FibNode node)
202 {
203 node.degree = 0;
204 node.parent = null;
205 node.child = null;
206 node.left = node;
207 node.right = node;
208 node.mark = false;
209
210 insertRoot(node);
211
212 if (min == null || node.key < min.key) {
213 min = node;
214 }
215 count++;
216 }
217
218 /*
219 * 合并两个堆
220 */
221 public void union(FibHeap heap)
222 {
223 if (heap.count == 0) return;
224
225 FibNode node = heap.root;
226 node.right.left = root.left;
227 root.left.right = node.right;
228 node.left.right = root;
229 root.left.left = node;
230
231 if (min == null || heap.min.key < min.key) {
232 min = heap.min;
233 }
234 count += heap.count;
235 }
236
237 /*
238 * 插入Root节点
239 */
240 private void insertRoot(FibNode node)
241 {
242 /*
243 * left node root
244 * O-----O-----O
245 */
246
247 node.left = root.left;
248 root.left.right = node;
249 node.right = root;
250 root.left = node;
251 }
252
253 static class FibNode
254 {
255 FibNode child;
256
257 FibNode left;
258
259 FibNode right;
260
261 FibNode parent;
262
263 int degree = 0;
264
265 boolean mark = false;
266
267 int key;
268
269
270 public FibNode() {}
271
272 public FibNode(int key)
273 {
274 this.key = key;
275 }
276 }
277
278 public static void main(String[] args)
279 {
280 FibHeap fh = new FibHeap();
281
282 int[] keys = { 9, 10, 5, 14, 12, 13, 8, 3 };
283 for (int i = 0; i < keys.length; i++) {
284 fh.insert(new FibNode(keys[i]));
285 }
286
287 FibHeap fh2 = new FibHeap();
288
289 int[] keys2 = { 3,7,2,7,9,14,66};
290 for (int i = 0; i < keys2.length; i++) {
291 FibNode fn=new FibNode();
292 fh2.insert(new FibNode(keys2[i]));
293 }
294
295 fh.union(fh2);
296 System.out.println(fh.min().key);
297
298 fh.displayRoot();
299 System.out.println("min:" + fh.extractMin().key);
300 System.out.println("min:" + fh.extractMin().key);
301 System.out.println("min:" + fh.extractMin().key);
302
303 fh.delete(fh.min());
304 System.out.println(fh.min().key);
305 }
306 }
