//  int right=-1;
   
    
    // 2 3 1 9 
 //   return arr;
    // 9 9 9 -1//
       int largest_right = -1;
   for(int i = arr.size() - 1; i>=0; i--){
       int temp = arr[i];
       if(arr[i] > largest_right){
           arr[i] = largest_right;
           largest_right = temp;
       }
       else
           arr[i] = largest_right;
   }
return arr;   
}