How to write a program to solve project euler problem 6 ?

/*
* Project Name: Problem Six
* Solution Name: Problem Six
* Original creation date: 06/07/2011
* Edit date: 18/01/2013
* Programmer name: Jamie Taylor (aka "GaProgMan")
* File name: ProblemSix.c
*
* Purpose of this project:
* Problem Six, from Project Euler.
* URL: http://projecteuler.net/index.php?section=problems&id=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.
*
* GNU Copyright information
* Copyright 2011 Jamie Taylor <jamie@taylorj.org.uk>
*
* This program is free software; you can redistribute
* it and/or modify it under the terms of the GNU General
* Public License as published by the Free Software
*Foundation; either version 2 of the License, or (at
*your option) any later version.
*
*This program is distributed in the hope that it will
*be useful, but WITHOUT ANY WARRANTY; without even the
*implied warranty of MERCHANTABILITY or FITNESS FOR A
*PARTICULAR PURPOSE. See the GNU General Public
*License for more details.
*
*You should have received a copy of the GNU General
*Public License along with this program; if not, write
*to the Free Software Foundation, Inc., 51 Franklin
*Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

#include <iostream>
#include <math.h>

using namespace std;

int main () {
unsigned long long sumOfSquares = 0;
unsigned long long squareOfSums = 0;
long long difference = 0;
int i = 1;
do {
sumOfSquares += pow((double)i, 2);
squareOfSums += i;
i++;
} while ( i < 101 );

squareOfSums = pow ((double)squareOfSums, 2);
difference = squareOfSums - sumOfSquares;

cout << "Sum of all squares: " << sumOfSquares << endl;
cout << "Square of all sums: " << squareOfSums << endl;

cout << "The difference between the sum of all squares and the square "
<< "of all sums is:\n" << difference << endl;
char ch;
/* cin >> ch; */
return 0;
}

/* Small changes to this file by <ahiliation@yahoo.co.in> Jeffrin Jose T. */
/* The pow() function returns the value of x raised to the power of y. */