contains duplicate solution

Author: nancyel

contains-duplicate/nancyel.ts

@@ -0,0 +1,14 @@
+/**
+ * time complexity: O(n)
+ * space complexity: O(n)
+ */
+function containsDuplicate(nums: number[]): boolean {
+  const seen = new Set();
+  for (let num of nums) {
+    if (seen.has(num)) {
+      return true;
+    }
+    seen.add(num);
+  }
+  return false;
+}