How to find all taxicab numbers less than N?

Question

A taxicab number is an integer that can be expressed as the sum of two cubes of integers in two different ways: a^3+b^3 = c^3+d^3. Design an algorithm to find all t

Answer 1

A easy way of understanding Time complexity O(N^2 logN), space complexity O(N) is to think it as a merge of N sorted arrays plus a bookkeeping of the previously merged element.