PROBLEM LINK:
Author: Sudhanshu Gupta
Tester: Sudhanshu Gupta
Editorialist: Sudhanshu Gupta
DIFFICULTY:
HARD
PREREQUISITES:
Math
PROBLEM:
For a given positive integer N find the number of all pairs (a, b) of positive integers such that 1 <= a < b <= N and the sum a + b divides the product a * b.
EXPLANATION:
SOLUTIONS:
Solution can be found here.