1 #include <stdio.h>
2 #include <stdlib.h>
3 //author : pgdnxu@qq.com
4
5 struct NODE
6 {
7 NODE *left;
8 NODE *right;
9 NODE *pa;
10 int data;
11 };
12
13 struct BST
14 {
15 NODE *root;
16 int nodenum;
17 };
18
19 NODE *search(int data,NODE *n)
20 {
21 if(NULL == n)
22 return NULL;
23 if(data < n->data)
24 return search(data,n->left);
25 else if(data > n->data)
26 return search(data,n->right);
27 else
28 return n;
29 }
30 NODE *find(int data,BST *t)
31 {
32 if(NULL == t)
33 return NULL;
34 return search(data,t->root);
35 }
36
37 NODE *insert(int data,NODE **n,NODE *p)
38 {
39 if(NULL == (*n))
40 {
41 (*n) = (NODE*)malloc(sizeof(NODE));
42 (*n)->left = NULL;
43 (*n)->right = NULL;
44 (*n)->pa = p;
45 (*n)->data = data;
46 return *n;
47 }
48 if(data < (*n)->data)
49 {
50 //left
51 return insert(data,&((*n)->left),*n);
52 }
53 else
54 {
55 return insert(data,&((*n)->right),*n);
56 }
57 }
58
59 NODE *addNode(BST **t,int data)
60 {
61 if(NULL == (*t))
62 {
63 (*t) = (BST*)malloc(sizeof(BST));
64 (*t)->root = NULL;
65 (*t)->nodenum = 0;
66 }
67 (*t)->nodenum++;
68 return insert(data,&((*t)->root),NULL);
69 }
70 void init(BST **t,int data[],int num)
71 {
72 int i;
73 NODE *tmp;
74 for(i=0;i<num;i++) {="" tmp="addNode(t,data[i]);" }="" void="" printtree(node="" *n,int="" deep)="" int="" i;="" for(i="0;i<deep;i++)" printf("="" ");="" if(null="=" n)="" printf("null\n");="" else="" if(n-="">pa == NULL)
75 printf("%d--|\n",n->data);
76 else
77 printf("%d(p:%d)--|\n",n->data,n->pa->data);
78 if(NULL != n)
79 {
80 printTree(n->left,deep+1);
81 printTree(n->right,deep+1);
82 }
83 }
84
85 void splay(NODE *n)
86 {
87 //error
88 if(NULL == n)
89 return;
90 NODE *nPa = n->pa;
91 NODE *nPaPa = nPa == NULL ? NULL : nPa->pa;
92 NODE *nPaPaPa=NULL;
93 int lr = -1;
94 if(nPaPa != NULL)
95 nPaPaPa = nPaPa->pa;
96 if(nPaPaPa != NULL)
97 {
98 if(nPaPa == nPaPaPa->left)
99 {
100 //left
101 lr = 0;
102 }
103 else
104 {
105 //right
106 lr = 1;
107 }
108 }
109 //root return
110 if(nPa == NULL)
111 {
112 return;
113 }
114 else if(nPaPa == NULL && n == nPa->left)
115 {
116 //zig
117 printf("proc: zig\n");
118 nPa->left = n->right;
119 if(n->right != NULL)
120 n->right->pa = nPa;
121 n->pa = nPa->pa;
122 nPa->pa = n;
123 n->right = nPa;
124 }
125 else if(nPaPa == NULL && n == nPa->right)
126 {
127 //zag
128 printf("proc: zag\n");
129 nPa->right = n->left;
130 if(n->left != NULL)
131 n->left->pa = nPa;
132 n->pa = nPa->pa;
133 nPa->pa = n;
134 n->left = nPa;
135 }
136 else if(n == nPa->left && nPa == nPaPa->left)
137 {
138 //zig-zig
139 printf("proc: zig-zig\n");
140
141 nPaPa->left = nPa->right;
142 nPa->pa = nPaPa->pa;
143 nPaPa->pa = nPa;
144 nPa->right = nPaPa;
145
146 nPa->left = n->right;
147 if(n->right != NULL)
148 n->right->pa = nPa;
149 n->pa = nPa->pa;
150 nPa->pa = n;
151 n->right = nPa;
152
153 if(lr != -1)
154 {
155 if(lr == 0)
156 nPaPaPa->left = n;
157 else if(lr == 1)
158 nPaPaPa->right = n;
159 }
160 if(n->pa != NULL)
161 splay(n);
162 }
163 else if(n == nPa->right && nPa == nPaPa->right)
164 {
165 //zag-zag
166 printf("proc: zag-zag\n");
167
168 nPaPa->right = nPa->left;
169 nPa->pa = nPaPa->pa;
170 nPaPa->pa = nPa;
171 nPa->left = nPaPa;
172
173 nPa->right = n->left;
174 if(n->left != NULL)
175 n->left->pa = nPa;
176 n->pa = nPa->pa;
177 nPa->pa = n;
178 n->left = nPa;
179
180 if(lr != -1)
181 {
182 if(lr == 0)
183 nPaPaPa->left = n;
184 else if(lr == 1)
185 nPaPaPa->right = n;
186 }
187 if(n->pa != NULL)
188 splay(n);
189 }
190 else if(n == nPa->left && nPa == nPaPa->right)
191 {
192 //zig-zag
193 printf("proc: zig-zag\n");
194 nPa->left = n->right;
195 n->pa = nPa->pa;
196 nPa->pa = n;
197 n->right = nPa;
198
199 nPaPa->right = n->left;
200 if(n->left != NULL)
201 n->left->pa = nPaPa;
202 n->pa = nPaPa->pa;
203 nPaPa->pa = n;
204 n->left = nPaPa;
205
206 if(lr != -1)
207 {
208 if(lr == 0)
209 nPaPaPa->left = n;
210 else if(lr == 1)
211 nPaPaPa->right = n;
212 }
213 if(n->pa != NULL)
214 splay(n);
215 }
216 else if(n == nPa->right && nPa == nPaPa->left)
217 {
218 //zag-zig
219 printf("proc: zag-zig\n");
220 nPa->right = n->left;
221 n->pa = nPa->pa;
222 nPa->pa = n;
223 n->left = nPa;
224
225 nPaPa->left = n->right;
226 if(n->right != NULL)
227 n->right->pa = nPaPa;
228 n->pa = nPaPa->pa;
229 nPaPa->pa = n;
230 n->right = nPaPa;
231
232 if(lr != -1)
233 {
234 if(lr == 0)
235 nPaPaPa->left = n;
236 else if(lr == 1)
237 nPaPaPa->right = n;
238 }
239 if(n->pa != NULL)
240 splay(n);
241 }
242 }
243
244 NODE *sfind(int data,BST *t)
245 {
246 if(NULL == t)
247 return NULL;
248 NODE *tar = search(data,t->root);
249 if(tar != NULL)
250 {
251 splay(tar);
252 t->root = tar;
253 }
254 else
255 printf("tar is NULL!\n");
256 return tar;
257 }
258
259
260 int main()
261 {
262 int a[] = {6,5,4,3,2,1};
263 BST *tree;
264 init(&tree,a,6);
265
266 //case 1
267 printf("========= case 1 =========\n");
268 printTree(tree->root,0);
269 sfind(1,tree);
270 printf("--------------------------\n");
271 printTree(tree->root,0);
272 printf("==========================\n");
273 //case 2
274 printf("========= case 2 =========\n");
275 printTree(tree->root,0);
276 sfind(2,tree);
277 printf("--------------------------\n");
278 printTree(tree->root,0);
279 printf("==========================\n");
280
281 return 0;
282 }
283 </num;i++)></stdlib.h></stdio.h>
