contains duplicate

Author: pastelto

contains-duplicate/pastelto.java

@@ -0,0 +1,14 @@
+/*
+    Return true when array contains duplicated number
+ */
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        HashSet<Integer> set = new HashSet<>();
+
+        for (int num : nums) {
+            if (set.contains(num)) return true;
+            set.add(num);
+        }
+        return false;
+    }
+}