Рандомная генерация чисел

#include <iostream>
#include <stdio.h>
#include <iomanip>
#include <conio.h>
 
using namespace std;
 
int main()
{
    float a = 9, b, x, y, alpha = 1;
    int score = 1;
 
    cout << "Enter b[2, 10] = ";
    cin >> b;
    cout << "Enter x = ";
    cin >> x;
 
    cout << "<#>" << "\t";
    cout << setw(10) << "<y>" << "\t";
    cout << setw(10) << "<x>" << "\t";
    cout << setw(10) << "<alpha>" << endl;
    cout << "===================================================================================" << endl;
    cout << setiosflags(ios::left);
    for (int i = 0 && score; i < 10 && score < 10; score++)
    {
        y = cos(x) + 1 / b * cos(a * x + 1) + 1 / (b * b) * cos(a * a * x + 2) + 1 / (b * b * b) * cos(a * a * a * x + 3) + 1 / (b * b * b * b) * cos(a * a * a * a * x + 4);
        cout << setw(10) << score << "\t";
        cout << setw(10) << y << "\t";
        cout << setw(10) << x << "\t";
        cout << setw(10) << alpha << endl;
        x = x + alpha * rand() % (1 + (-1));
    }
}

#include <iostream>
#include <random>
 
int main() {
    std::random_device rd;
    std::mt19937_64 gen(rd());
    std::uniform_int_distribution<> dist(-1, 1);
 
    for (unsigned i = 0; i < 100; ++i) {
        std::cout << dist(gen) << std::endl;
    }
 
    return 0;
}

#include <iostream>
#include <cstdlib>
#include <ctime>
 
int main() {
    srand(time(nullptr));
    
    const int a = -1;
    const int b = 1;
 
    for (unsigned i = 0; i < 100; ++i) {
        std::cout << a + rand() % (b - a + 1) << std::endl;
    }
 
    return 0;
}