Question

Which of the following is the correct mathematical application of Euclid’s algorithm?

(a) Determination of prime numbers

(b) Lagrange’s four square theorem

(c) Cauchy-Euler theorem

(d) Residue theorem

I got this question in a job interview.

This is a very interesting question from Number Theory in division Number Theory of Data Structures & Algorithms II

Answer 1

The correct choice is (b) Lagrange’s four square theorem

Easy explanation - Lagrange’s four square theorem is one of the mathematical applications of Euclid’s algorithm and it is the basic tool for proving theorems in number theory. It can be generalized into other types of numbers like the Gaussian integers.