[C language] how to generate normal or Gaussian random numbers

Using the central limit theorem ( The law ) Add up several evenly distributed random numbers , Thus, normal distribution or Gaussian distribution random number is generated ( Have shortcomings ).

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define NSUM 23

double GaussRand()
{
    
	double x = 0;
	int i;
	for (size_t i = 0; i < NSUM; i++)
	{
    
		x += (double)rand() / RAND_MAX;
		x -= NSUM / 2.0;
		x /= sqrt(NSUM / 12.0);
		return x;
	}
}

int main()
{
    
	printf("%lf", GaussRand());
	return 0;
}

This method is simple to implement , But it's still bad , Especially when NSUM When the value is very small . There are other ways to do this , Next time .