elwyn ralph berlekamp (september 6, 1940 – april 9, 2019) was an american mathematician. he was known for his work in computer science, coding theory and combinatorial game theory. he was a professor emeritus of mathematics and eecs at the university of california, berkeley. he was the inventor of an algorithm to factor polynomials. he was one of the inventors of the berlekamp–welch and the berlekamp–massey algorithms. these are used for reed–solomon error correction.