Amicable numbers | Project Euler | Problem #21
URL to the problem page: https://projecteuler.net/problem=21 Let d(n) be defined as the sum of proper divisors of n (numbers less than n which divide evenly into n). If d(a) = b and d(b) = a, where a ≠ b, then a and b are an amicable pair and each of a and b are called amicable numbers. For example, the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110; therefore d(220) = 284. The proper divisors of 284 are 1, 2, 4, 71 and 142; so d(284) = 220. Evaluate the sum of all the amicable numbers under 10000. #include <iostream> using namespace std ; int main () { long long i, j, b, a, result = 0 , counter, counter2, sum, number; for (i = 1 ; i < 10000 ; i++) { counter = 0 ; a = 0 ; sum...
