/*
 *  ============================================================================
 *  arrays.c : The purposes of this C program are:
 * 
 *  (a) To read daily rainfalls for one week, and compute the range and average.
 *  (b) Demonstrates use of one-dimensional arrays, and output to a file.
 *  ============================================================================
 */

#include <stdio.h>
#include <stdlib.h>

#define max(a, b) ((a) > (b) ? (a) : (b))

/* Forward declaration of the function fileOut */

void fileOut( float faRainfall[], float fAv );

enum { MaxDays = 7 };

int main( void ) {
float faRainfall[ MaxDays ];   /* store the rainfall for each day in the week: */
float fSum = 0.0;
float fMax = 0.0;
float fAv  = 0.0;
int iDay;                      /* day counter: */

  /* [a] : initialize the rainfall for each day to zero */

     for( iDay = 1; iDay <= MaxDays; iDay++ )
          faRainfall[ iDay-1 ] = 0.0;

  /* [b] : Prompt the user for the rainfall for each day: */

     for( iDay = 1; iDay <= MaxDays; iDay++ ) {
          printf( "Enter the rainfall (in inches) for day %d -->", iDay );
          scanf( "%f%*c", &faRainfall[ iDay-1 ] );
     }

  /* [c] : Print the maximum and average rainfall for the week: */

     for( iDay = 1; iDay <= MaxDays; iDay++ )  {
          fMax = max( fMax, faRainfall[ iDay-1 ] );
          fSum += faRainfall[ iDay-1 ];
     }

     fAv = fSum/MaxDays;
     printf("\nThe maximum amount of rain this week was %f inches\n", fMax );
     printf(  "The average rainfall this week was %f inches      \n", fAv );

  /* [d] : Write details of rainfall to output file  */

     fileOut( faRainfall, fAv);
}

/*
 *  ==============================================================
 *  function 'fileOut' to write the data to a file called RAIN.TXT
 *  ==============================================================
 */

void fileOut( float faRainfall[], float fAv ) {
FILE *fpRain;          /* typedef struct, defined in stdio.h */
int     iDay;          /* day counter                        */

     fpRain = fopen("RAIN.TXT", "w+");

     for ( iDay = 1; iDay <= MaxDays; iDay++ )
        fprintf( fpRain, "%f %f \n", faRainfall[ iDay-1 ], fAv );

     fclose( fpRain );
}