//====================================================== file = qsort.c =====
//=  Program to sort a list of floating point (double) numbers              =
//===========================================================================
//=  Notes:                                                                 =
//=    1) Input from input file "in.dat" to stdin (see example below)       =
//=        * No comments are allowed                                        =
//=    2) Output is to stdout                                               =
//=-------------------------------------------------------------------------=
//= Example "in.dat" file:                                                  =
//=                                                                         =
//=    1.0                                                                  =
//=    1.0                                                                  =
//=    28.0                                                                 =
//=    6.0                                                                  =
//=    9.0                                                                  =
//=    2.0                                                                  =
//=    19.0                                                                 =
//=    19.0                                                                 =
//=-------------------------------------------------------------------------=
//= Example output (for above "in.dat")                                     =
//=                                                                         =
//=    1.000000                                                             =
//=    1.000000                                                             =
//=    2.000000                                                             =
//=    6.000000                                                             =
//=    9.000000                                                             =
//=    19.000000                                                            =
//=    19.000000                                                            =
//=    28.000000                                                            =
//=-------------------------------------------------------------------------=
//=  Build: bcc32 qsort.c                                                   =
//=-------------------------------------------------------------------------=
//=  Execute: qsort < in.dat                                                =
//=-------------------------------------------------------------------------=
//=  Author: Ken Christensen                                                =
//=          University of South Florida                                    =
//=          WWW: http://www.csee.usf.edu/~christen                         =
//=          Email: christen@csee.usf.edu                                   =
//=-------------------------------------------------------------------------=
//=  History: KJC (07/25/07) - Genesis                                      =
//===========================================================================
//----- Include files -------------------------------------------------------
#include <stdio.h>                 // Needed for printf() and feof()
#include <stdlib.h>                // Needed for exit(), atof(), and qsort()

//----- Defines -------------------------------------------------------------
#define MAX_SIZE      2000000      // Maximum size of time series data array

//----- Globals -------------------------------------------------------------
double     X[MAX_SIZE];            // Time series read from "in.dat"
int        N;                      // Number of values in "in.dat"

//----- Function prototypes -------------------------------------------------
int  comp(const void *p, const void *q);    // Compare p and q for qsort()

//===========================================================================
//=  Main program                                                           =
//===========================================================================
void main(void)
{
  char  tempString[1024];          // Temporary string variable
  int   i;                         // Loop counter

  // Load the series X
  N = 0;
  while(1)
  {
    scanf("%s", tempString);
    if (feof(stdin)) break;

    // Put value in array and increment array index
    X[N] = atof(tempString);
    N++;

    // Check if MAX_SIZE data values exceeded
    if (N >= MAX_SIZE)
    {
      printf("*** ERROR - greater than %d data values \n", MAX_SIZE);
      exit(1);
    }
  }

  // Sort the series X using ANSI C qsort() function
  qsort(X, N, sizeof(double), comp);

  // Output the sorted list
  for (i=0; i<N; i++)
    printf("%f \n", X[i]);
}

//===========================================================================
//=  Function to compare two arguments in an array of double                =
//=   - As needed by qsort()                                                =
//===========================================================================
int  comp(const void *p, const void *q)
{
  double *ptr1 = (double *)(p);
  double *ptr2 = (double *)(q);

  if (*ptr1 < *ptr2)
    return -1;
  else if (*ptr1 == *ptr2)
    return 0;
  else
    return 1;
}