w01: 217. Contains Duplicate

Author: Heeseung Koo

contains-duplicate/nrudev.ts

@@ -0,0 +1,9 @@
+function containsDuplicate(nums: number[]): boolean {
+  const map = new Map<number, number>();
+
+  for (let i = 0; i < nums.length; i++) {
+    if (map.has(nums[i])) return true;
+    map.set(nums[i], 1);
+  }
+  return false;
+}