Find common elements in three sorted arrays

Program -

public class common{

     public static void main(String []args){
        
        int ar1[] = {1, 5, 10, 20, 40, 80};
        int ar2[] = {6, 7, 20, 80, 100};
        int ar3[] = {3, 4, 15, 20, 30, 70, 80, 120};
        int i = 0, j = 0, k = 0;
        
        while (i < ar1.length && j < ar2.length && k < ar3.length)
        {
            if (ar1[i] == ar2[j] && ar2[j] == ar3[k])
            {   
                System.out.print(ar1[i]+" ");   
                i++; j++; k++;
            }
            else if (ar1[i] < ar2[j])
                 i++;
            else if (ar2[j] < ar3[k])
                 j++;
            else
                 k++;
        }
     }
}

Video explanation -