Euler Problem 006

The problem

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 = 552 = 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.

Solution

The code is not that interesting. You simply walk from 1 to the number keeping track of the differences and return them in the end. Not a bad way to warm up for the day, but definitely isn’t going to keep thinking forever.

var findDifferenceOfSquares = function(number){
  var differences = [];
  var sum = 0;
  var sumOfSquares = 0;
  for(var i = 1; i < number + 1; i++) {
    sum += i;
    sumOfSquares += i * i;
    differences.push(sum*sum - sumOfSquares);
  }
  return differences;
}

If you’d like to see the full code please see my daily toy problem exercises that I’ve been working on. It includes tests and a README.