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

      float T;
      int main

{
        union  { unsigned int i[2]; time_t d;} t;
        t.d=time(NULL);
        srand(t.i[0]);
       
       RandInvNormal(double mean, double stdev);
       
       T=3*mean;
       printf("T=%f\n",T);


}



double RandInvNormal(double mean, double stdev)
{/* Inverse Normal cumulative distribution function.
   FUNCTION PROVIDED TO STUDENTS FROM MODULE WEB-SITE.
   Returns a "random" value from a Normal distribution with given "mean" and "stdev"

   Adapted from [url]http://home.online.no/~pjacklam/notes/invnorm/[/url]
   Note: The following libraries are needed:
        #include <stdlib.h>
        #include <time.h>
   Start of main function should include following code to "seed" random number generator:
        union  { unsigned int i[2]; time_t d;} t;
        t.d=time(NULL);
        srand(t.i[0]);
*/

{
        // Define constants to curve fit for integral
        const double A1 = -3.969683028665376e+01;
        const double A2 = 2.209460984245205e+02;
        const double A3 = -2.759285104469687e+02;
        const double A4 =  1.383577518672690e+02;
        const double A5 = -3.066479806614716e+01;
        const double A6 =  2.506628277459239e+00;

        const double B1 = -5.447609879822406e+01;
        const double B2 =  1.615858368580409e+02;
        const double B3 = -1.556989798598866e+02;
        const double B4 =  6.680131188771972e+01;
        const double B5 = -1.328068155288572e+01;

        const double C1 = -7.784894002430293e-03;
        const double C2 = -3.223964580411365e-01;
        const double C3 = -2.400758277161838e+00;
        const double C4 = -2.549732539343734e+00;
        const double C5 = 4.374664141464968e+00;
        const double C6 = 2.938163982698783e+00;

        const double D1 = 7.784695709041462e-03;
        const double D2 = 3.224671290700398e-01;
        const double D3 = 2.445134137142996e+00;
        const double D4 = 3.754408661907416e+00;

        const double P_LOW = 0.02425;
        const double P_HIGH = 0.97575;  // P_high = 1 - p_low

        double p, q, r, x;

        do
        {
           p = (float)(rand())/RAND_MAX;     // Get a random number between 0 and 1



                                                // rand() returns an int between 0 and RAND_MAX
        } while (p <= 0 || p >= 1);             // Repeat making sure p is not 0 or 1

        if (p > 0 && p < P_LOW)
        {
                q = sqrt(-2*log(p));
                x = (((((C1*q+C2)*q+C3)*q+C4)*q+C5)*q+C6) / ((((D1*q+D2)*q+D3)*q+D4)*q+1);
        } else if (p >= P_LOW && p <= P_HIGH)
        {
                q = p - 0.5;
                r = q*q;
                x = (((((A1*r+A2)*r+A3)*r+A4)*r+A5)*r+A6)*q /(((((B1*r+B2)*r+B3)*r+B4)*r+B5)*r+1);
        } else {
                q = sqrt(-2*log(1-p));
                x = -(((((C1*q+C2)*q+C3)*q+C4)*q+C5)*q+C6) / ((((D1*q+D2)*q+D3)*q+D4)*q+1);
        }

        return (mean + x*stdev);
}
}

/* the headers */
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>

/* function prototype */
double RandInvNormal(double mean, double stdev);

int main()
{
    union {
        unsigned int i[2];
        time_t d;
    } t;
    double mean, stdev;
    double x;

    t.d = time(NULL);
    srand(t.i[0]);

    mean = 1.0;
    stdev = 1.0;

    /* put the next two statements in a loop if you want */
    x = RandInvNormal(mean, stdev);
    printf("x = %f\n", x);

    return 0;
}

/* now put the code for RandInvNormal() here: */
double RandInvNormal(double mean, double stdev)
{
    /* Define constants to curve fit for integral */
    const double A1 = -3.969683028665376e+01;
    const double A2 = 2.209460984245205e+02;
.
.
.
.
}