Генератор дробных чисел в диапазоне от - 5 до 5

random = (-50 + rand() % 100) / 10.0;   // генератор дробных чисел в диапазоне  от - 5 до 5

#include <random>
 
double rnd(double min = -5.0, double max = 5.0) {
    static std::random_device rd;
    static std::mt19937 mt(rd());
    std::uniform_real_distribution<double> dis(min, max);
    return dis(mt);
}

void RangedRandDemo(int range_min, int range_max)
{
    // Generate random numbers in the interval [range_min, range_max], inclusive.
        // Note: This method of generating random numbers in a range isn't suitable for
        // applications that require high quality random numbers.
        // rand() has a small output range [0,32767], making it unsuitable for
        // generating random numbers across a large range using the method below.
        // The approach below also may result in a non-uniform distribution.
        // More robust random number functionality is available in the C++ <random> header.
        // See https://learn.microsoft.com/cpp/standard-library/random
        int r = ((double)rand() / RAND_MAX) * (range_max - range_min) + range_min;
        printf("  %6d\n", r);
}
int main(void)
{
    printf("\nRandom number in a range demo ====\n\n");
    RangedRandDemo(-5.,5.);
}