1 /*接口头文件*/
2 typedef int ElementType;
3
4 #ifndef _SEARCHTREE_H
5 #define _SEARCHTREE_H
6
7 struct TreeNode;
8 typedef struct TreeNode * PtrToNode;
9 typedef PtrToNode Position;
10 typedef PtrToNode SearchTree;
11
12 /*操作集*/
13 SearchTree MakeEmpty( SearchTree T );
14 Position Find( ElementType X, SearchTree T );
15 Position FindMin( SearchTree T );
16 Position FindMax( SearchTree T );
17 SearchTree Insert( ElementType X, SearchTree T );
18 SearchTree Delete( ElementType X, SearchTree T );
19 ElementType Retrieve( Position P );
20 void PrintfTree( SearchTree T );
21
22 #endif
1 /*接口实现*/
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include "searchtree.h"
5
6 /*特定结构体定义*/
7 struct TreeNode
8 {
9 ElementType Element;
10 SearchTree Left;
11 SearchTree Right;
12 };
13
14 SearchTree MakeEmpty( SearchTree T )
15 {
16 if ( T != NULL )
17 {
18 MakeEmpty( T->Left );
19 MakeEmpty( T->Right );
20 free( T );
21 }
22
23 return NULL;
24 }
25
26 Position Find( ElementType X, SearchTree T )
27 {
28 if ( T == NULL )
29 return NULL;
30
31 if ( X < T->Left )
32 return Find( X, T->Left ); //尾递归
33 else if ( X > T->Element )
34 return Find( X, T->Right ); //尾递归
35 else
36 return T;
37 }
38
39 /*递归例程*/
40 Position FindMin( SearchTree T )
41 {
42 if ( T == NULL )
43 return NULL; //No Found
44 else if ( T->Left == NULL ) //左子树不存在
45 return T;
46 else
47 return FindMin( T->Left );
48 }
49
50 /*
51 非递归例程
52 Position FindMin( SearchTree T )
53 {
54 if ( T != NULL )
55 while ( T->Left != NULL )
56 T = T->Left;
57
58 return T;
59 }
60 */
61
62 /*递归例程*/
63 Position FindMax( SearchTree T )
64 {
65 if ( T == NULL )
66 return NULL;
67 else if ( T->Right == NULL )
68 return T;
69 else
70 return FindMax( T->Right );
71 }
72
73 /*
74 非递归例程
75 Position FindMax( SearchTree T )
76 {
77 if ( T != NULL )
78 while ( T->Right != NULL )
79 T = T->Right;
80
81 return T;
82 }
83 */
84
85 SearchTree Insert( ElementType X, SearchTree T )
86 {
87 if ( T == NULL )
88 {
89 T = ( SearchTree )malloc( sizeof( struct TreeNode ) );
90 if ( T == NULL )
91 {
92 printf( "No Space!!!\n" );
93 exit( 1 );
94 }
95 T->Element = X;
96 T->Left = NULL;
97 T->Right = NULL;
98 }
99 else if ( X < T->Element )
100 T->Left = Insert( X, T->Left );
101 else if ( X > T->Element )
102 T->Right = Insert( X, T->Right );
103
104 return T;
105 }
106
107 SearchTree Delete( ElementType X, SearchTree T )
108 {
109 Position Temp;
110
111 if ( T == NULL )
112 {
113 printf( "No Found!!!\n" );
114 exit( 1 );
115 }
116 else if ( X < T->Element )
117 T->Left = Delete( X, T->Left );
118 else if ( X < T->Element )
119 T->Right = Delete( X, T->Right );
120 else if ( T->Left != NULL && T->Right != NULL )
121 {
122 Temp = FindMin( T->Right );
123 T->Element = Temp->Element;
124 T->Right = Delete( T->Element, T->Right );
125 }
126 else
127 {
128 Temp = T;
129 if ( T->Left == NULL )
130 T = T->Right;
131 else if ( T->Right == NULL )
132 T = T->Left;
133
134 free( Temp );
135 }
136
137 return T;
138 }
139
140 void PrintfTree( SearchTree T )
141 {
142 if ( T != NULL )
143 {
144 PrintfTree( T->Left );
145 printf( "%3d", T->Element );
146 PrintfTree( T->Right );
147 }
148
149 }
