contains duplicate solution

Author: smosco

contains-duplicate/smosco.js

@@ -0,0 +1,8 @@
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+const containsDuplicate = (nums) => {
+  let uniqueNumSet = new Set(nums);
+  return uniqueNumSet.size !== nums.length;
+};