Pythagorean quadruples | Rosetta Code | #9

URL to the problem page: https://rosettacode.org/wiki/Pythagorean_quadruples


One form of Pythagorean quadruples is (for positive integers a, b, c, and d):
a² + b² + c² = d²

     An example:
2² + 3² + 6² = 7²
which is: 4 + 9 + 36 = 49

For positive integers up 2,200 (inclusive), for all values of a, b, c, and d, find (and show here) those values of d that can't be represented.

(Note: this task takes too much time if you compile the program in Debug Mode/x86. I recommend to compile the program in Release Mode/x64, and with the OpenMP if possible. (by including <omp.h> library, enabling OpenMP from the project settings and using " #pragma omp parallel for " in the code.) Because it reduces the amount of time to complete the task even more.)

#include <iostream>

#include <omp.h>

using namespace std;

int main()

{

#pragma omp parallel for

    for (long long int i = 1; i <= 2200; i++) {

        int cnt = 0;

        for (long long int j = 1; j < 2200; j++) {

            if (pow(j, 2) > pow(i, 2)) {

                break;

            }

            for (long long int k = 1; k < 2200; k++) {

                if (pow(k, 2) > pow(i, 2) || (pow(j, 2) + pow(k, 2)) > pow(i, 2)) {

                    break;

                }

                for (long long int l = 1; l < 2200; l++) {

                    if ((pow(j, 2) + pow(k, 2) + pow(l, 2)) == pow(i, 2)) {

                        cnt++;

                        break;

                    }

                    else if (pow(l, 2) > pow(i, 2) || pow(k, 2) + pow(l, 2) > pow(i, 2) || (pow(j, 2) + pow(k, 2) + pow(l, 2)) > pow(i, 2)) {

                        break;

                    }

                }

                if (cnt != 0) {

                    break;

                }

            }

            if (cnt != 0) {

                break;

            }

        }

        if (cnt == 0) {

            cout << i << " can not be represented." << endl;

        }

    }

    return 0;

}

CLICK TO SEE THE OUTPUT.