Add week 1 solutions: contains-duplicate

Author: gitsunmin

contains-duplicate/gitsunmin.ts

@@ -0,0 +1,8 @@
+/**
+ * https://leetcode.com/problems/contains-duplicate/
+ * time complexity : O(n)
+ * space complexity : O(n)
+ */
+function containsDuplicate(nums: number[]): boolean {
+    return new Set(nums).size !== nums.length
+};