Create 297-serialize-and-deserialize-binary-tree.js

Author: everthis

297-serialize-and-deserialize-binary-tree.js

@@ -0,0 +1,55 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+
+/**
+ * Encodes a tree to a single string.
+ *
+ * @param {TreeNode} root
+ * @return {string}
+ */
+const serialize = function(root) {
+  return rserialize(root, "");
+};
+
+function rserialize(root, str) {
+  if (root === null) {
+    str += "null,";
+  } else {
+    str += root.val + ",";
+    str = rserialize(root.left, str);
+    str = rserialize(root.right, str);
+  }
+
+  return str;
+}
+/**
+ * Decodes your encoded data to tree.
+ *
+ * @param {string} data
+ * @return {TreeNode}
+ */
+const deserialize = function(data) {
+  let data_array = data.split(",").filter(el => el !== "");
+  return rdeserialize(data_array);
+};
+
+function rdeserialize(l) {
+  if (l[0] === "null") {
+    l.shift();
+    return null;
+  }
+  const root = new TreeNode(+l[0]);
+  l.shift();
+  root.left = rdeserialize(l);
+  root.right = rdeserialize(l);
+  return root;
+}
+/**
+ * Your functions will be called as such:
+ * deserialize(serialize(root));
+ */