removing duplicates form an array

#include<iostream>
using namespace std;

int removeduplicates(int arr[] , int n){

int size = 1;
for(int i=1; i<n; i++){

if(arr[size-1]!=arr[i]){
  arr[size] = arr[i];
  size++;
}

}

return size;

}

int main() {

  int arr[] = {10, 20, 20, 30, 30, 30}, n = 6;

  cout<<"Before Removal"<<endl;

   for(int i = 0; i < n; i++)
   {
   		cout<<arr[i]<<" ";
   }

   cout<<endl;

   n = removeduplicates(arr, n);

   cout<<"After Removal"<<endl;

   for(int i = 0; i < n; i++)
   {
   		cout<<arr[i]<<" ";
   }

}