#include <stdio.h>         
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <stdbool.h>
#include <signal.h>
#include <unistd.h>
#include <limits.h>
#include <time.h>
#define NUM 100000000000

/* MT code */
#define N 624
#define M 397
#define MATRIX_A 0x9908b0df  
#define UPPER_MASK 0x80000000 
#define LOWER_MASK 0x7fffffff 
#define TEMPERING_MASK_B 0x9d2c5680
#define TEMPERING_MASK_C 0xefc60000
#define TEMPERING_SHIFT_U(y)  (y >> 11)
#define TEMPERING_SHIFT_S(y)  (y << 7)
#define TEMPERING_SHIFT_T(y)  (y << 15)
#define TEMPERING_SHIFT_L(y)  (y >> 18)

static unsigned long mt[N];
static int mti=N+1;
// Random number generator. MUST BE CHANGED TO THE LATEST VERSION LATER. MIGHT BE FASTER
void sgenrand(unsigned long seed)
{
    mt[0]= seed & 0xffffffff;
    for (mti=1; mti<N; mti++)
        mt[mti] = (69069 * mt[mti-1]) & 0xffffffff;
}

 float Genrand()
{
    unsigned long y;
    static unsigned long mag01[2]={0x0, MATRIX_A};

    if (mti >= N) { 
        int kk;

        if (mti == N+1)   
	  sgenrand((unsigned long)time(0)); 

        for (kk=0;kk<N-M;kk++) {
            y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
            mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1];
        }
        for (;kk<N-1;kk++) {
            y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
            mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1];
        }
        y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
        mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1];

        mti = 0;
    }

    y = mt[mti++];
    y ^= TEMPERING_SHIFT_U(y);
    y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B;
    y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C;
    y ^= TEMPERING_SHIFT_L(y);

    return ( (float)y * 2.3283064370807974e-10 ); 
}


main()
{
  register long int i; 
  time_t t0, t1;
  clock_t c0, c1;
  struct timespec ti, tf;
  t0=time(NULL);
  c0=clock();
  printf("Initial wall time = %ld\t Initial clock time = %d\n",(long)t0,(int)c0);
  for(i=1;i<=NUM;i++)
    {
      Genrand();
    }
  t1=time(NULL);
  c1=clock();
  printf("Final wall time = %ld\t Final clock time = %d\n",(long)t1,(int)c1);
  printf("Elapsed wall clock time = %ld\n",(long)(t1-t0));
  printf("Elapsed CPU time = %f\n",(float)(c1-c0)/CLOCKS_PER_SEC);
  return(0);
}