gistfile1.txt

//The sum of the squares of the first ten natural numbers is,
//12 + 22 + ... + 102 = 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.*/

int sumofall(int a);

#include <stdio.h>

int main(int argc, char **argv)
{
	int g, r, answer, f;

	f = 0;
	g = sumofall(100) * sumofall(100);

	for(r = 1;r <= 100; r++)
	{
		f += r*r;

	}

	answer = g - f;
	printf("%d", answer);
	return 0;
}

int sumofall(int a)
{
	return (a / 2) * (a + 1);

}