Merge pull request neetcode-gh#2698 from tahzeer/main

Create 0450-delete-node-in-a-bst.cpp

cpp/0450-delete-node-in-a-bst.cpp

@@ -0,0 +1,46 @@
+/**
+ * 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) {}
+ * };
+ */
+
+// Time: O(h)
+// Space: O(1)
+class Solution {
+public:
+ TreeNode* deleteNode(TreeNode* root, int key) {
+ if(root == nullptr) return root;
+
+ if(root->val > key) {
+ root->left = deleteNode(root->left, key);
+ }
+ else if(root->val < key) {
+ root->right = deleteNode(root->right, key);
+ }
+
+ // perform deletion if root->val == key
+ else {
+ if(!root->left) return root->right;
+ if(!root->right) return root->left;
+
+ // both left and right subtrees are not null
+ // traverse the right subtree to find the minimum/leftmost value
+ // (or) travel the left subtree to find the maximum/rightmost value
+ TreeNode* temp = root->right;
+ while(temp->left) {
+ temp = temp->left;
+ }
+ root->val = temp->val;
+
+ root->right = deleteNode(root->right, temp->val);
+ }
+
+ return root;
+ }
+};