feat: add solutions for contains-duplicate and valid-anagram

Author: 01-binary

contains-duplicate/01-binary.js

@@ -0,0 +1,7 @@
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function (nums) {
+  return nums.length !== [...new Set(nums)].length;
+};

valid-anagram/01-binary.js

@@ -0,0 +1,8 @@
+/**
+ * @param {string} s
+ * @param {string} t
+ * @return {boolean}
+ */
+var isAnagram = function (s, t) {
+  return s.split('').sort().join() === t.split('').sort().join();
+};