Euler in Groovy 6: sum of squares vs square of sums

by Paul Agapow
in programming

The sum of the squares of the first ten natural numbers is, 1^2 + 2^2 + ... + 10^2 = 385. The square of the sum of the first ten natural numbers is (1 + 2 + ... + 10)^2 = 55^2 = 3025. Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025 - 385 = 2640. Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum:

sum_of_squares = 0
square_of_sum = 0
(1..100).each {
        sum_of_squares += it * it
        square_of_sum += it
}
square_of_sum *= square_of_sum
return square_of_sum - sum_of_squares
// => 25164150