Create: 0217-contains-duplicate.dart

Author: NikSWE

dart/0217-contains-duplicate.dart

@@ -0,0 +1,15 @@
+// Time Complexity: O(n)
+// Space Complexity: O(n)
+
+class Solution {
+  bool containsDuplicate(List<int> nums) {
+    Set<int> hashSet = Set<int>();
+    for (int n in nums) {
+      if (hashSet.contains(n)) {
+        return true;
+      }
+      hashSet.add(n);
+    }
+    return false;
+  }
+}