//====================================================== file = delta.c =====
//=  Program to output deltas between values for a series X of size N       =
//===========================================================================
//=  Notes:                                                                 =
//=    1) Input from input file "in.dat" to stdin (see example below)       =
//=        * Comments are bounded by "&" characters at the beginning and    =
//=          end of the comment block                                       =
//=    2) Output is to stdout                                               =
//=-------------------------------------------------------------------------=
//= Example "in.dat" file:                                                  =
//=                                                                         =
//=    & Sample series of data which can be integers or reals. &            =
//=    & There are 11 values in this file.                     &            =
//=    50                                                                   =
//=    42                                                                   =
//=    48                                                                   =
//=    61                                                                   =
//=    60                                                                   =
//=    53                                                                   =
//=    39                                                                   =
//=    54                                                                   =
//=    42                                                                   =
//=    59                                                                   =
//=    53                                                                   =
//=-------------------------------------------------------------------------=
//= Example output (for above "in.dat"):                                    =
//=                                                                         =
//=   c:\work\delta < in.dat                                                =
//=   ------------------------------------------------- delta.c -----       =
//=   -8.000000                                                             =
//=   6.000000                                                              =
//=   13.000000                                                             =
//=   -1.000000                                                             =
//=   -7.000000                                                             =
//=   -14.000000                                                            =
//=   15.000000                                                             =
//=   -12.000000                                                            =
//=   17.000000                                                             =
//=   -6.000000                                                             =
//=   ---------------------------------------------------------------       =
//=-------------------------------------------------------------------------=
//=  Build: bcc32 delta.c                                                   =
//=-------------------------------------------------------------------------=
//=  Execute: summary1 < delta                                              =
//=-------------------------------------------------------------------------=
//=  Author: Ken Christensen                                                =
//=          University of South Florida                                    =
//=          WWW: http://www.csee.usf.edu/~christen                         =
//=          Email: christen@csee.usf.edu                                   =
//=-------------------------------------------------------------------------=
//=  History: KJC (05/26/18) - Genesis                                      =
//===========================================================================
//----- Include files -------------------------------------------------------
#include <stdio.h>                 // Needed for printf() and feof()
#include <stdlib.h>                // Needed for exit() and atof()
#include <string.h>                // Needed for strcmp()

//----- Defines -------------------------------------------------------------
#define MAX_SIZE 10000000          // Maximum size of time series data array

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

//----- Function prototypes -------------------------------------------------
void   load_X_array(void);         // Load X array

//===========================================================================
//=  Main program                                                           =
//===========================================================================
void main(void)
{
  double   delta;                    // Delta value
  int      i;                        // Loop counter

  // Malloc space for X
  X = (double *) malloc(sizeof(double) * MAX_SIZE);
  if (X == NULL)
  {
    printf("*** ERROR - Could not malloc() enough space \n");
    exit(1);
  }

  // Load the series X
  printf("------------------------------------------------- delta.c -----\n");
  load_X_array();

  // Loop to compute min, max, sum, first moment (mean), and second moment
  for (i=0; i<(N-1); i++)
  {
    delta = X[i+1] - X[i];
    printf("%f \n", delta);
  }
  printf("---------------------------------------------------------------\n");

  // Free the malloced memory
  free(X);
}

//===========================================================================
//=  Function to load X array from stdin and determine N                    =
//===========================================================================
void load_X_array(void)
{
  char      temp_string[1024];     // Temporary string variable

  // Read all values into X
  N = 0;
  while(1)
  {
    scanf("%s", temp_string);
    if (feof(stdin)) goto end;

    // This handles a comment (multiple comments are handled)
    if (strcmp(temp_string, "&") == 0)
    {
      while(1)
      {
        do
        {
          scanf("%s", temp_string);
        } while (strcmp(temp_string, "&") != 0);
        scanf("%s", temp_string);
        if (strcmp(temp_string, "&") != 0) break;
      }
      if (feof(stdin)) goto end;
    }

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

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

  // End-of-file escape
  end:

  return;
}