Simple reinforcement learning methods to learn CartPole

I've been experimenting with OpenAI gym recently, and one of the simplest environments is CartPole. The problem consists of balancing a pole connected with one joint on top of a moving cart. The only actions are to add a force of -1 or 1 to the cart, pushing it left or right. In this post, I will be going over some of the methods described in the CartPole request for research, including implementations and some intuition behind how they work. In CartPole's environment, there are four observations at any given state, representing information such as the angle of the pole and the position of the cart.