#include <stdlib.h>

double* ES(const double x[])
{
    static double result[1] = {0};

    result[0] = x[0]*x[0] + x[1]*x[1] + x[2]*x[2];

    return result;
}

double* gradientES(const double x[])
{
    static double v[3];

    v[0] = 2 * x[0];
    v[1] = 2 * x[1];
    v[2] = 2 * x[2];

    return v;
}