1. Department of Computer Science, University of the Punjab, Lahore 54000, Pakistan
2. Mathematics Department, Faculty of Science, Taibah University, Al-Madinah Al-Munawarah, Saudi Arabia
3. Department of Mathematics, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan
4. Department of Sciences and Technology, Ranyah University College, Taif University, P. O. Box 11099, Taif 21944, Saudi Arabia