Contains-duplicate

Author: mkwkw

contains-duplicate/mkwkw.java

@@ -0,0 +1,21 @@
+//using map
+
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        Map<Integer, Boolean> appearance = new HashMap<>();
+
+        for(int i=0; i<nums.length; i++)
+        {
+            if(appearance.containsKey(nums[i]))
+            {
+                return true;
+            }
+            else
+            {
+                appearance.put(nums[i], true);
+            }
+        }
+
+        return false;
+    }
+}