should I cite or quote?

I seem to be in a dilemma when it comes to citation and references. I am implementing and improving an algorithm, therefore I must state the steps of the algorithm. I would also like to use the definitions they used and there is not much room for paraphrasing. If I paraphrase it, it would be weird since the formulation is very specific. This is a general question when implementing some algorithm in a paper, would I cite the definitions or should I quote ?

Thank you