//МНГС
#include <iostream>
using namespace std;
double function(double x[]){
    return x[0]*x[0]+x[0]*x[1]+x[1]*x[1]-2*x[0]+x[1];
}
int main() {
    double u;
    double a[2][2];
    double b[2], x1[2], e1[2],q1[2],aq[2], pr1[2], pr[2], xtest[2];
    double t[2];
    double x2=100000, min=100000, shag;
    double ort[1]={0};
    //init
    a[0][0]=2;a[0][1]=1;a[1][0]=1;a[1][1]=2;
    b[0]=-2;b[1]=1;
    x1[0]=0;x1[1]=0;
    e1[0]=1;e1[1]=0;
    int br;
    while(abs(function(x1)-x2)>1e-6){
        min = 100000;
        for (int p=0;p<2;p++){
        for (int i=0;i<=1;i++){
            xtest[i]=x1[i];
            if (i==p){
                ort[i]=1;
            }
            else ort[i]=0;
        }
        x2 = function(x1);
        for (int i=0;i<=1;i++){
            double s = b[i];
            for(int j=0;j<=1;j++){
                s+=a[i][j]*xtest[j];
            }
            q1[i]=s;
        }
        //A*ort
        for (int i=0;i<=1;i++){
            double s;
            s=0;
            for(int j=0;j<=1;j++){
                s+=a[i][j]*ort[j];
            }
            aq[i]=s;
        }
        double u;
        u = -q1[p]/aq[p];
        xtest[p]+=u;
        if (function(xtest)<min) {
            min = function(xtest);
            br = p;
            shag = u;
        }
        }
        x1[br] = x1[br] + shag;
    }
    cout<<"Point x: "<<endl;
    for (int i=0;i<2;i++){
        cout<<x1[i]<<" ";
    }
    cout<<endl;
    cout<<"f(x): "<<endl<<function(x1)<<endl;

    system("pause");
    return 0;
}