diff --git a/Array/findDuplicate.cpp b/Array/findDuplicate.cpp
new file mode 100644
index 0000000..a1cbffd
--- /dev/null
+++ b/Array/findDuplicate.cpp
@@ -0,0 +1,44 @@
+// Find duplicate in array
+
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution{
+  public:
+    vector<int> duplicates(int arr[], int n) 
+    {
+        int hash[n]={0};
+        vector<int>v;
+        for(int i=0;i<n;i++)
+        {
+            hash[arr[i]]++;
+        }
+        for(int i=0;i<n;i++)
+        {
+            if(hash[i]>1)
+            v.push_back(i);
+        }
+        if(v.size()==0)
+        {
+            v.push_back(-1);
+            return v;
+        }
+        return v;
+    }
+};
+
+int main() {
+    int t;
+    cin >> t;
+    while (t-- > 0) {
+        int n;
+        cin >> n;
+        int a[n];
+        for (int i = 0; i < n; i++) cin >> a[i];
+        Solution obj;
+        vector<int> ans = obj.duplicates(a, n);
+        for (int i : ans) cout << i << ' ';
+        cout << endl;
+    }
+    return 0;
+}