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

Author: benmak11

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

@@ -0,0 +1,34 @@
+/** 
+ * TC : log (n)
+ * 
+ * */ 
+class Solution {
+    public TreeNode minimumVal(TreeNode root) {
+        TreeNode curr = root;
+        while (curr != null && curr.left != null) {
+            curr = curr.left;
+        }
+        return curr;
+    }
+
+    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.left == null) {
+                return root.right;
+            } else if (root.right == null) {
+                return root.left;
+            } else {
+                TreeNode minVal = minimumVal(root);
+                root.val = minVal.val;
+                root.right = deleteNode(root.right, minVal.val);
+            }
+        }
+        return root;
+    }
+}