What is the time complexity of this code and how can we optimize it further

import java.util.* ;
  
class GFG
{
  
    static void AlternateRearrange(int arr[], int n) 
    { 
        // Sort the array
          
        // Collection.sort() sorts the
        // collection in ascending order
        Arrays.sort(arr) ;
          
        ArrayList v1 = new ArrayList(); // to insert even values 
        ArrayList v2 = new ArrayList(); // to insert odd values 
      
        for (int i = 0; i < n; i++) 
            if (arr[i] % 2 == 0) 
                v1.add(arr[i]); 
            else
                v2.add(arr[i]); 
      
        int index = 0, i = 0, j = 0; 
      
        boolean flag = false; 
      
        // Set flag to true if first element is even 
        if (arr[0] % 2 == 0) 
            flag = true; 
      
        // Start rearranging array 
        while (index < n) 
        { 
      
            // If first element is even 
            if (flag == true) 
            { 
                arr[index] = v1.get(i); 
                i += 1 ;
                index += 1 ;
                flag = !flag; 
            } 
      
            // Else, first element is Odd 
            else
            { 
                arr[index] = v2.get(j) ; 
                j += 1 ;
                index += 1 ;
                flag = !flag; 
            } 
        } 
      
        // Print the rearranged array 
        for (i = 0; i < n; i++) 
            System.out.print(arr[i] + " "); 
    } 
      
    // Driver code 
    public static void main(String []args) 
    { 
        int arr[] = { 9, 8, 13, 2, 19, 14 }; 
        int n = arr.length ;
      
        AlternateRearrange(arr, n); 
    } 
}