Create 114-flatten-binary-tree-to-linked-list.js

Author: everthis

114-flatten-binary-tree-to-linked-list.js

@@ -0,0 +1,26 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {void} Do not return anything, modify root in-place instead.
+ */
+
+const flatten = function(root) {
+  let prev = null
+  function op(root) {
+    if (root == null) return;
+    op(root.right);
+    op(root.left);
+    root.right = prev;
+    root.left = null;
+    prev = root;
+  }
+  op(root)
+};
+
+