-
Notifications
You must be signed in to change notification settings - Fork 0
/
450. Delete Node in a BST.cpp
64 lines (55 loc) · 1.54 KB
/
450. Delete Node in a BST.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
// https://leetcode.com/problems/delete-node-in-a-bst/
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution
{
public:
TreeNode *deleteNode(TreeNode *root, int key)
{
if (root == nullptr)
return root;
if (root->val < key)
root->right = deleteNode(root->right, key);
else if (root->val > key)
root->left = deleteNode(root->left, key);
else
{
if (root->left == nullptr && root->right == nullptr)
root = nullptr;
else if (root->left != nullptr)
{
root->val = inorderPredecessor(root);
root->left = deleteNode(root->left, root->val);
}
else
{
root->val = inorderSuccessor(root);
root->right = deleteNode(root->right, root->val);
}
}
return root;
}
int inorderPredecessor(TreeNode *root)
{
root = root->left;
while (root->right)
root = root->right;
return root->val;
}
int inorderSuccessor(TreeNode *root)
{
root = root->right;
while (root->left)
root = root->left;
return root->val;
}
};