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DeleteANodeINABST.txt
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DeleteANodeINABST.txt
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/**
* 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 {
//int inordersuccessor(TreeNode* root);
//int inorderprecessor(TreeNode* root);
public:
TreeNode* deleteNode(TreeNode* root, int key)
{
if(root==NULL)
return NULL;
if(key>root->val)
root->right=deleteNode(root->right,key);
else
if(key<root->val)
root->left=deleteNode(root->left,key);
else
{
if(!root->right && !root->left)
{
root=NULL;
}
else
if(root->left)
{
root->val=inorderprecessor(root); //left thean right
root->left=deleteNode(root->left,root->val);
}
else
{
root->val=inordersuccessor(root);//right than left
root->right=deleteNode(root->right,root->val);
}
}
return root;
}
int inordersuccessor(TreeNode* root)
{
root=root->right;
while(root->left)
{
root=root->left;
}
return root->val;
}
int inorderprecessor(TreeNode* root)
{
root=root->left;
while(root->right)
{
root=root->right;
}
return root->val;
}
};