1 INTRODUCTION

2 PRELIMINARIES  
2.1 Recommender Systems  
2.2 From Reinforcement Learning to Deep Reinforcement Learning  
2.3 Why Reinforcement Learning for Recommendation?  
2.4 Problem Formulation  
2.5 Proposed RLRS Framework  

3 REINFORCEMENT LEARNING BASED RECOMMENDER SYSTEMS ALGORITHMS  
3.1 RL-based RSs  
3.2 DRL-based RSs  

4 EMERGING TOPICS

5 OPEN RESEARCH DIRECTIONS

6 CONCLUSION