85 在二叉查找树中插入节点

 1 #include <iostream>
 2 #include <vector>
 3 #include <math.h>
 4 #include <string>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 class TreeNode 
 9 {
10 public:
11     int val;
12     TreeNode *left, *right;
13     TreeNode(int val)
14     {
15         this->val = val;
16         this->left = this->right = NULL;
17     }
18 
19 
20     TreeNode * insertNode(TreeNode * root, TreeNode * node) //插入位置需要进行判断;
21     {
22         int nodeValue=node->val;
23         TreeNode *p=new TreeNode(nodeValue);
24 
25         if (root==NULL)
26         {
27             root=p;
28             return root;
29         }
30         TreeNode *tempp=root;
31         while(tempp!=NULL)   //注意循环终止条件，无论怎么判断tempp都不可能为NULL，所以要用return语句结束函数的执行;
32         {
33             if (nodeValue<tempp->val)
34             {
35                 if (tempp->left==NULL)
36                 {
37                     tempp->left=p;
38                     return root;
39                 }
40                 else
41                 {
42                     tempp=tempp->left;
43                 }
44             }
45             else
46             {
47                 if (tempp->right==NULL)
48                 {
49                     tempp->right=p;
50                     return root;
51                 }
52                 else
53                 {
54                     tempp=tempp->right;
55                 }
56             }
57         }
58         
59     }
60 
61     TreeNode * insertnode(TreeNode * root, TreeNode * node);
62 };
63 

64 TreeNode* TreeNode::insertnode(TreeNode * root, TreeNode * node)  //使用递归;
65 {
66     if (root==NULL)
67     {
68         root=node;
69         return root;
70     }
71     if (node->val<root->val)
72     {
73         root->left=insertnode(root->left,node);
74     }
75     else
76     {
77         root->right=insertnode(root->right,node);
78     }
79     return root;
80 }