containsDuplicate solution

Author: Sol35229

contains-duplicate/Sol35229.java

@@ -0,0 +1,27 @@
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+public class Sol35229 {
+
+    public boolean containsDuplicate(int[] nums) {
+        Set<Integer> duplicateCheck = new HashSet<>();
+        for (int i = 0; i < nums.length; i++) {
+            if (duplicateCheck.contains(nums[i])) {
+                return true;
+            }
+            duplicateCheck.add(nums[i]);
+        }
+        return duplicateCheck.size() != nums.length;
+    }
+
+    public boolean containsDuplicate2(int[] nums) {
+        Arrays.sort(nums);
+        for (int i = 0; i < nums.length-1; i++) {
+            if (nums[i] == nums[i+1]) {
+                return true;
+            }
+        }
+        return false;
+    }
+}