I will describe how two neural circuits in the brain solve fundamental computer science problems in unique ways. The first is the fruit fly olfactory circuit, which keeps track of the number of times different stimuli (odors) are experienced using a “count sketch” algorithm. The second is the mouse neuromuscular circuit, which efficiently generates muscle forces to actuate motor movements using a “bipartite matching” algorithm. Both examples highlight my lab's overarching goal of uncovering the natural algorithms that underlie biological function.