Наибольший из треугольников, образованных точками плоскости

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

struct POINT {
    double x;
    double y;
};
typedef POINT * PPOINT;

struct TRIANGLE {
    double a;
    double b;
    double c;
    POINT first;
    POINT second;
    POINT third;
    bool exists();
    void lengths();
    double area();
};

double edge(const POINT, const POINT);
void show(PPOINT, size_t);
double max_area(TRIANGLE &, PPOINT, size_t);

int main() {
    wcout.imbue(locale("rus_rus.866"));
    wcout << L"\n Введите количество точек: ";
    size_t size;
    cin >> size;
    cout << endl;

    PPOINT points = new POINT [size];

    for (size_t n = 0; n < size; n++) {
        cout << " x" << n + 1 << " -> ";
        cin >> points[n].x;
        cout << " y" << n + 1 << " -> ";
        cin >> points[n].y;
        cout << endl;
    } system("cls");

    show(points, size);

    TRIANGLE max_triangle;
    double max = max_area(max_triangle, points, size);

    if (max) {
        wcout << L"  Наибольшую площадь имеет треугольник образованный точками с координатами:\n\n"
              << L"\t\t\t\tx1 = " << max_triangle.first.x << endl
              << L"\t\t\t\ty1 = " << max_triangle.first.y << endl << endl
              << L"\t\t\t\tx2 = " << max_triangle.second.x << endl
              << L"\t\t\t\ty2 = " << max_triangle.second.y << endl << endl
              << L"\t\t\t\tx3 = " << max_triangle.third.x << endl
              << L"\t\t\t\ty3 = " << max_triangle.third.y << endl << endl
              << L"\t\t\tПлощадь треугольника: " << max << endl;
    } else wcout << L" Недостаточно данных!\a\n";

    delete[] points;

    cin.get(); cin.get();
    return 0;
}

double TRIANGLE::area() {
    double p = (a + b + c) / 2;
    return sqrt(p * (p - a) * (p - b) * (p - c));
}

bool TRIANGLE::exists() {
    bool x;
    double max = (a > b) ? (a > c) ? a : c : (b > c) ? b : c;
    (a + b + c - max > max) ? x = true : x = false;
    return x;
}

void TRIANGLE::lengths() {
    a = edge(first, second);
    b = edge(second, third);
    c = edge(third, first);
}

double max_area(TRIANGLE & _tr, PPOINT _points, size_t _size) {
    double max = 0;
    if (_size > 2) {
        double area;
        TRIANGLE temp;
        for (size_t f = 0; f < _size - 2; f++) {
            for (size_t s = f + 1; s < _size - 1; s++) {
                for (size_t t = s + 1; t < _size; t++) {
                    _tr.first = _points[f];
                    _tr.second = _points[s];
                    _tr.third = _points[t];
                    _tr.lengths();
                    area = _tr.area();
                    if (_tr.exists() && area > max) {
                        max = area;
                        temp = _tr;
                    }
                }
            }
        } _tr = temp;
    }
    return max;
}

void show(PPOINT _points, size_t _size) {
    streamsize w = 7;
    cout << endl << "  X: ";
    for (size_t n = 0; n < _size; n++) cout << setw(w) << _points[n].x;
    cout << endl << "  Y: ";
    for (size_t n = 0; n < _size; n++) cout << setw(w) << _points[n].y;
    cout << endl << endl;
}

double edge(const POINT _a, const POINT _b) {
    return sqrt(pow(_a.x - _b.x, 2) + pow(_a.y - _b.y, 2));
}