1 //与上一次实现不同，这里使用了大量的指针引用，
2 //因此节省了一个指向父节点的指针
3 #include<iostream>
4 #include<vector>
5 #include<ctime>
6 #include<cstdlib>
7
8 using namespace std;
9
10 template<class T>
11 class BinarySearchTree
12 {
13 private:
14 struct Node
15 {
16 T data;
17 Node *left;
18 Node *right;
19 Node(T val)
20 {
21 data = val;
22 left = NULL;
23 right = NULL;
24 }
25
26 private:
27 Node()
28 {
29 }
30 };
31 Node *root;
32 int size;
33
34 public:
35 BinarySearchTree()
36 {
37 root = NULL;
38 size = 0;
39 }
40 ~BinarySearchTree()
41 {
42 clear(root);
43 root = NULL;
44 size = 0;
45 }
46 Node*& findMin(Node *&node) const
47 {
48 if(node->left == NULL)
49 return node;
50 else
51 return findMin(node->left);
52 }
53 T max(Node *node) const
54 {
55 if(node->right == NULL)
56 return node->data;
57 else
58 return max(node->right);
59 }
60
61 Node *& insert(Node *& node,T val)
62 {
63 if(node == NULL)
64 {
65 node = new Node(val);
66 size++;
67 return node;
68 }
69 if(val > node->data)
70 return insert(node->right,val);
71 else if(val < node->data)
72 return insert(node->left,val);
73 else
74 return node;
75 }
76
77 bool contain(Node *& node,T val) const
78 {
79 if(node == NULL)
80 return false;
81
82 if(val > node->data)
83 return contain(node->right,val);
84 else if(val < node->data)
85 return contain(node->left,val);
86 else
87 return true;
88 }
89
90 void remove(Node* &node,T val)
91 {
92 if(node == NULL)
93 {
94 cout<<"remove() error!\n";
95 return;
96 }
97 if(val > node->data)
98 remove(node->right,val);
99 else if(val < node->data)
100 remove(node->left,val);
101 else if(val == node->data)
102 {
103 if(node->left == NULL && node->right == NULL)
104 {
105 delete node;
106 node = NULL;
107 }
108 else if(node->left == NULL && node->right != NULL)
109 {
110 Node *p = node;
111 node = node->right;
112 delete p;
113 size--;
114 }
115 else if(node->left != NULL && node->right == NULL)
116 {
117 Node *p = node;
118 node = node->left;
119 delete p;
120 size--;
121 }
122 else if(node->left != NULL && node->right != NULL)
123 {
124 Node* &p = findMin(node->right);
125 node->data = p->data;
126 p = p->right;
127 delete p;
128 size--;
129 }
130 }
131 }
132 void clear(Node* &node)
133 {
134 if(node->left != NULL)
135 clear(node->left);
136 if(node->right != NULL)
137 clear(node->right);
138
139 delete node;
140 node = NULL;
141 }
142 void print(Node *node)
143 {
144 if(node == NULL)
145 return;
146 cout<<node->data<< " ";
147 if(node->left != NULL)
148 print(node->left);
149 if(node->right != NULL)
150 print(node->right);
151 }
152 void insert(T val)
153 {
154 insert(root,val);
155 }
156 void remove(T val)
157 {
158 remove(root,val);
159 }
160 void print()
161 {
162 print(root);
163 cout<<"\n";
164 }
165 };
166
167 int main()
168 {
169 BinarySearchTree<int> tree;
170 tree.insert(10);
171 tree.insert(1);
172 tree.insert(11);
173 tree.insert(9);
174 tree.insert(8);
175 tree.print();
176 cout<<"\n\n";
177 tree.remove(9);
178 tree.print();
179
180 return 0;
181 }
时间： 2024-08-24 04:21:30