Terekhov RK#3

#include <iostream>
#include <vector>
#include <algorithm>
#include <iomanip>

using namespace std;

struct GenAl

{
    double x;
    double y;
    double f;
};

double function(const double& x, const double& y)
{
    return sin(x)/(1 + x*x + y*y);
}

double probability(const double& f1, const double& f2, const double& f3, const double& f4)
{
    return 1 - f1 / (f1 + f2 + f3 + f4);
}

int crossover(const double& p1, const double& p2, const double& p3, const double& p4)
{
    double value = rand()/(RAND_MAX/(p1 + p2 + p3 + p4));
    if (value < p1) return 0;
    if (value > p1 && value < (p1 + p2)) return 1;
    if (value > (p1 + p2) && value < (p1 + p2 + p3)) return 2;
    if (value > (p1 + p2 + p3) && value < (p1 + p2 + p3 + p4)) return 3;
}


double mutation(const double& gen)
{
    if (gen >= 0) return gen - 0.05;
    else return gen + 0.05;
}

int main()
{
    double ax = -2, bx = 2, ay = -2, by = 2;
    int n = 1;
    vector <GenAl> g(4);
    for (auto i = 0; i < 4; i++)
    {
        g[i].x = rand()/(RAND_MAX/2.0) - 2;
        g[i].y = rand() / (RAND_MAX / 2.0) - 2;
        g[i].f = function(g[i].x, g[i].y);
    }
    double avg = 0;
    cout << "0" << endl;
    cout << " x y f(x,y)" << endl;
    sort(g.begin(), g.end(), [](auto a, auto b) { return a.f < b.f; });
    for (auto i : g)

    {
        cout << fixed << setprecision(4) << setw(7) << i.x << " " << setw(7) << i.y << " " << setw(7) << i.f << " " << endl;
        avg += i.f;
    }
    avg /= 4;
    cout << endl << "max: " << g[3].f << " average: " << avg << endl << endl;
    while (n <= 50)
    {
        vector <double> prob(4);
        prob[0] = probability(g[0].f, g[1].f, g[2].f, g[3].f);
        prob[1] = probability(g[1].f, g[0].f, g[2].f, g[3].f);
        prob[2] = probability(g[2].f, g[1].f, g[0].f, g[3].f);
        prob[3] = probability(g[3].f, g[1].f, g[2].f, g[0].f);
        int i = crossover(prob[0], prob[1], prob[2], prob[3]);
        g.erase(g.begin() + i);
        g.push_back({});
        vector <GenAl> g_copy = g;
        g[0].x = g_copy[2].x;
        g[1].x = g_copy[2].x;
        g[2].x = g_copy[0].x;
        g[3].x = g_copy[1].x;
        g[0].y = g_copy[1].y;
        g[1].y = g_copy[0].y;
        g[2].y = g_copy[2].y;
        g[3].y = g_copy[2].y;
        for (auto i = 0; i < 4; i++)
        {
            if (rand() % 2 == 0) g[i].x = g[i].x - 0.05;
            else g[i].y = g[i].y - 0.05;
        }
        for (auto i = 0; i < 4; i++) g[i].f = function(g[i].x, g[i].y);
        double avg = 0;
        cout << n++ << " " << endl;
        cout << " x y f(x,y)" << endl;
        sort(g.begin(), g.end(), [](auto a, auto b) { return a.f < b.f; });
        for (auto i : g)
        {
            cout << fixed << setprecision(4) << setw(7) << i.x << " " << setw(7) << i.y << " " << setw(7) << i.f << " " << endl;
            avg += i.f;
        }
        avg /= 4;
        cout << endl << "max: " << g[3].f << " average: " << avg << endl << endl;
    }
    return 0;
}