Add solution #1290

Author: JoshCrozier

solutions/1290-convert-binary-number-in-a-linked-list-to-integer.js

@@ -0,0 +1,32 @@
+/**
+ * 1290. Convert Binary Number in a Linked List to Integer
+ * https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer/
+ * Difficulty: Easy
+ *
+ * Given `head` which is a reference node to a singly-linked list.
+ * The value of each node in the linked list is either 0 or 1.
+ * The linked list holds the binary representation of a number.
+ * Return the decimal value of the number in the linked list.
+ */
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {number}
+ */
+var getDecimalValue = function(head) {
+  let binary = String(head.val);
+
+  while (head.next !== null) {
+    head = head.next;
+    binary += head.val;
+  }
+
+  return parseInt(binary, 2);
+};