Leetcode-450 Delete Node in a BST(删除二叉搜索树中的节点) 

 1 class Solution
 2 {
 3     public:
 4         //if doesn't find,return NULL
 5         TreeNode *BinarySearchTreeNodeFindMin(TreeNode *TreeRoot)
 6         {
 7             if(TreeRoot==NULL)
 8             {
 9                 return NULL;
10             }
11             else if(TreeRoot->left==NULL)
12             {
13                 return TreeRoot;
14             }
15             else
16             {
17                 return BinarySearchTreeNodeFindMin(TreeRoot->left);
18             }
19         }
20         TreeNode* deleteNode(TreeNode* root, int key)
21         {
22             if(root == NULL)
23                 return NULL;
24 
25             TreeNode *TmpCell;
26 
27             if(key < root -> val)
28             {
29                 root -> left = deleteNode(root->left,key);
30             }
31             else if(key > root -> val)
32             {
33                 root -> right = deleteNode(root->right,key);
34             }
35             else
36             {
37                 if(root->left && root->right)
38                 {
39                     TmpCell = BinarySearchTreeNodeFindMin(root -> right);
40                     root -> val = TmpCell -> val;
41                     root -> right = deleteNode(root->right,root->val);
42                 }
43                 else
44                 {
45                     TmpCell = root;
46                     if(root->left==NULL)
47                     {
48                         root = root -> right;
49                     }
50                     else if(root->right==NULL)
51                     {
52                         root = root -> left;
53                     }
54                     free(TmpCell);
55                 }
56             }
57             return root;
58         }
59 };

 

posted @ 2018-08-17 09:25  Asurudo  阅读(305)  评论(0)    收藏  举报