数据域大小关系：
根>左，根<右
假设所有二叉树的所有结点数据都是正数，且两两不同
arr 6,3,8,2,5,1,7
1 #include <stdio.h>
2 #include <stdlib.h>
3
4 typedef struct node{
5 int data;
6 struct node* left;
7 struct node* right;
8 } Node;
9
10 typedef struct{
11 Node* root;
12 } Tree;
13
14 void insert(Tree* tree, int value)
15 {
16 Node* node= malloc(sizeof(Node));
17 node -> data = value;
18 node -> left = NULL;
19 node -> right = NULL;
20
21 if(tree -> root == NULL){
22 tree -> root = node;
23 return ;
24 }
25 else
26 {
27 Node* temp = tree -> root;
28 while(temp != NULL){
29 if(temp -> data > value){
30 //走左边有两种情况
31 if(temp -> left == NULL){
32 temp -> left = node;
33 return;
34 }
35 else
36 temp = temp -> left;
37 }
38 if(temp -> data < value){
39 if(temp -> right == NULL){
40 temp -> right = node;
41 return;
42 }
43 else
44 temp = temp -> right;
45 }
46 }
47 }
48 }
49 int get_height(Node* node)//为了便于递归的进行
50 {
51 if(node == NULL)
52 return 0;
53 else
54 {
55 int h_left = get_height(node -> left);
56 int h_right = get_height(node -> right);
57 int max = h_left;
58 if(max < h_right){
59 max = h_right;
60 }
61 return max + 1;
62 }
63 }
64 int get_maximum(Node* node)
65 {
66 if(node == NULL)
67 return -1;//所有节点全为正数时
68 else{
69 int m1 = get_maximum(node -> left);
70 int m2 = get_maximum(node -> right);
71 int m3 = node -> data;
72 int max = m1;
73 if(m2>max) {
74 max = m2;
75 }
76 if(m3>max){
77 max = m3;
78 }
79 return max;
80 }
81 }
82
83 void preorder(Node* node){
84 if(node != NULL){
85 printf("%d
",node -> data);
86 preorder(node -> left);
87 preorder(node -> right);
88 }
89 }
90 void inorder(Node* node){
91 if(node != NULL){
92 inorder(node -> left);
93 printf("%d
",node -> data);
94 inorder(node -> right);
95 }
96 }
97 void postorder(Node* node){
98 if(node != NULL){
99 postorder(node -> left);
100 postorder(node -> right);
101 printf("%d
",node -> data);
102 }
103 }
104
105 int main(){
106 Tree tree;
107 tree.root=NULL;
108
109 int arr[7]={6,3,8,2,5,1,7};
110
111 int i;
112 for(i=0; i<7; i++)
113 insert(&tree, arr[i]);
114
115 printf("h = %d
", get_height(tree.root));
116
117 printf("max = %d
", get_maximum(tree.root));
118
119 }
//----------------------------------
新增问题：
1）复制二叉树
刚拿到手时候，直接传指针，输不出来值。检查一番，发现犯了低级错误：直接传递指针变量，因为此时传递的是指针变量的指向，相当于实体变量。
Node* Copy(Node* ExtN,Node* newN){ //复制二叉树，中序方法 if(ExtN == NULL){ return NULL; } else { newN = (Node*)malloc(sizeof(Node)); newN -> data = ExtN -> data; newN -> left = Copy(ExtN -> left, newN -> left); newN -> right = Copy(ExtN -> right,newN -> right); return newN; } } ... int main(){ //... Tree newT; newT.root=Copy(tree.root, newT.root); preorder(newT.root); //复制二叉树 //... }
2）计算结点个数
1 int Count(Node *node){ 2 //统计节点总数 3 if(node == NULL){ 4 return 0; 5 } 6 else{ 7 return Count(node -> left)+ 8 Count(node -> right)+1; 9 } 10 }
3）统计叶子个数
1 int countLeaf(Node *node){ 2 //统计叶子结点的个数 3 if(node == NULL) 4 return 0; 5 if(node -> left == NULL && node -> right == NULL) 6 return 1; 7 else{ 8 return countLeaf(node -> left) + countLeaf(node -> right); 9 } 10 }