Add solution #450

Author: JoshCrozier

README.md

@@ -262,6 +262,7 @@
 442|[Find All Duplicates in an Array](./0442-find-all-duplicates-in-an-array.js)|Medium|
 443|[String Compression](./0443-string-compression.js)|Medium|
 448|[Find All Numbers Disappeared in an Array](./0448-find-all-numbers-disappeared-in-an-array.js)|Easy|
+450|[Delete Node in a BST](./0450-delete-node-in-a-bst.js)|Medium|
 451|[Sort Characters By Frequency](./0451-sort-characters-by-frequency.js)|Medium|
 452|[Minimum Number of Arrows to Burst Balloons](./0452-minimum-number-of-arrows-to-burst-balloons.js)|Medium|
 456|[132 Pattern](./0456-132-pattern.js)|Medium|

solutions/0450-delete-node-in-a-bst.js

@@ -0,0 +1,48 @@
+/**
+ * 450. Delete Node in a BST
+ * https://leetcode.com/problems/delete-node-in-a-bst/
+ * Difficulty: Medium
+ *
+ * Given a root node reference of a BST and a key, delete the node with the given key in
+ * the BST. Return the root node reference (possibly updated) of the BST.
+ *
+ * Basically, the deletion can be divided into two stages:
+ * 1. Search for a node to remove.
+ * 2. If the node is found, delete the node.
+ */
+
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @param {number} key
+ * @return {TreeNode}
+ */
+var deleteNode = function(root, key) {
+  if (!root) 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 === null) {
+      return root.right;
+    } else if (root.right === null) {
+      return root.left;
+    } else {
+      let node = root.right;
+      while (node.left) {
+        node = node.left;
+      }
+      node.left = root.left;
+      return root.right;
+    }
+  }
+  return root;
+};