Create 450-delete-node-in-a-bst.js

Author: everthis

450-delete-node-in-a-bst.js

@@ -0,0 +1,32 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @param {number} key
+ * @return {TreeNode}
+ */
+const deleteNode = function(root, key) {
+    if(root == null) return null
+    if (root.val > key) {
+        root.left = deleteNode(root.left, key)
+    } else if(root.val < key) {
+        root.right = deleteNode(root.right, key)
+    } else {
+        if (root.left == null) {
+            return root.right
+        }
+        if (root.right == null) {
+            return root.left
+        }
+        let rightSmallest = root.right
+        while(rightSmallest.left != null) rightSmallest = rightSmallest.left
+        rightSmallest.left = root.left
+        return root.right
+    }
+    return root
+};