Sum Square Difference

// https://projecteuler.net/problem=6

// 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.

// Answer: 25164150

#include <iostream>

int sum_squares(size_t size)
{
  int sum_square = 0;
  int square_sum = 0;

  for(size_t i = (size+1); --i ;)
  {
    sum_square += (i*i);
    square_sum += i;
  }

  return ((square_sum*square_sum) - sum_square);
}

#if ! defined UNITTEST_MODE
int main(int argc, char const *argv[])
{
  std::cout << "Answer: " << sum_squares(100) << std::endl;
}
#endif

package org.tvarley.euler.solutions;

import org.tvarley.euler.Solution;

public class Solution006 implements Solution {
  public String solve() {
    int n = 100;
    long sumOfSquares = n * (n + 1) * (2 * n + 1) / 6;
    long squareOfSum = n * n * (n + 1) * (n + 1) / 4;
    long difference = squareOfSum - sumOfSquares;
    return Long.toString(difference);
  }
}

module.exports = {
  answer : () => {
    var sum_square = 0;
    var square_sum = 0;
    var size = 100;

    for(i = (size + 1); --i ;)
    {
      sum_square += (i * i);
      square_sum += i;
    }

    return ((square_sum * square_sum) - sum_square);
  }
};

def solve():
    """
    Sum square difference
    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.
    """
    n = 100
    sum_sq = sum(i**2 for i in range(1, n+1))
    sq_sum = sum(range(1, n+1))**2
    return sq_sum - sum_sq

def sum_squares(limit)
  sum_square = 0
  square_sum = 0

  (0..limit).each do |i|
    sum_square += (i * i)
    square_sum += i
  end
  (square_sum * square_sum) - sum_square
end

puts sum_squares(100) if __FILE__ == $PROGRAM_NAME

package main

import "fmt"

func main() {

    n := 100

    sum := 0

    sumSq := 0

    for i := 1; i <= n; i++ {

        sum += i

        sumSq += i * i

    }

    sqSum := sum * sum

    diff := sqSum - sumSq

    fmt.Println(diff)

}

// https://projecteuler.net/problem=6

// 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.

// Answer: 25164150

pub fn sum_squares(size: u32) -> u32
{
    let mut sum_square = 0;
    let mut square_sum = 0;

    for i in 1..size + 1 {
        sum_square += i * i;
        square_sum += i;
    }

    return (square_sum * square_sum) - sum_square;
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn euler_006() {
        assert_eq!(sum_squares(100), 25_164_150);
    }
}