Pi estimation using only uniformally random numbers

pi_estimate.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>

double random_uniform(void) { return (double)rand() / (double)RAND_MAX; }

long double estimate_pi(int iter) {
    int num_points_in_circle = 0, num_points_total = 0;
    
    for (int i = 0; i < iter; ++i) {
        double x = random_uniform();
        double y = random_uniform();

        long double distance = pow(x, 2) + pow(y, 2);
        num_points_in_circle += 1 * (distance <= 1);

        num_points_total++;
    }

    return 4.0 * num_points_in_circle/num_points_total;
}


int main(int argc, char* argv[]) {
    srand(time(NULL));

    long double res = estimate_pi(atoi(argv[1]));
    printf("%Lf\n", res);

    return 0;
}