# Project Euler Problem 6

December 14, 2011

I mentioned yesterday, I’ve been doing the first few problems of Project Euler and figured I’d share my solution to problem 6 here.

**The Problem**

Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

**The Solution**

This one is pretty straight forward. Find a data structure capable of holding the square of the sum of numbers 1 to 100 and subtract the squares of the first 100 natural numbers.

```
#include
using namespace std;
int main () {
unsigned long sumsquares = 0, sums = 0;
int n;
cout <> n;
while (n < 0) {
cout <> n;
}
for(int i = 1; i <= n; i++) {
cout << "i: " << i << endl;
sumsquares += i * i;
cout << "sumsquares: " << sumsquares << endl;
sums += i;
cout << "sums: " << sums << endl;
}
cout << "The sum of squares from 1 to " << n << ": " << sumsquares << endl;
cout << "The square of sums from 1 to " << n << ": " << sums * sums << endl << endl;
cout << "The difference: " << (sums * sums - sumsquares) << endl;
return(0);
}
```

As you can see, there is a loop creating the sum and the sum of squares. From there, it subtracts the square of the sum and the sum of squares to get the answer.