Create 331-verify-preorder-serialization-of-a-binary-tree.js

Author: everthis

331-verify-preorder-serialization-of-a-binary-tree.js

@@ -0,0 +1,13 @@
+/**
+ * @param {string} preorder
+ * @return {boolean}
+ */
+const isValidSerialization = function(preorder) {
+    const nodes = preorder.split(',')
+    let diff = 1
+    for(let node of nodes) {
+      if(--diff < 0) return false
+      if(node !== '#') diff += 2
+    }
+    return diff === 0
+};