Ian Dorian Macleod
Problem 9
Problem Statement

A Pythagorean triplet is a set of three natural numbers, a < b < c, for which,

a2 + b2 = c2

For example, 32 + 42 = 9 + 16 = 25 = 52.

There exists exactly one Pythagorean triplet for which a + b + c = 1000.
Find the product abc.

Approach

C++ implementation

#include <stdc++.h>
using namespace std;

int main() {
int result = 0;

for(int m = 2; m < 100; m++) {
for(int n = 1; n < m; n++) {
if ((pow(m, 2) - pow(n, 2) + 2*m*n + pow(m,2) + pow(n,2)) == 1000) {
result = (pow(m, 2) - pow(n, 2)) * 2*m*n * (pow(m,2) + pow(n,2));
break;
}
}
}
cout << result << endl;
return 0;
}

You can also download the source code for this problem here and compile it on your local machine.
Further Analysis