/*
 *  =======================================================================
 *  prog_rainfall.c : The purposes of this C program are:
 * 
 *    (a) To read daily rainfalls for one week, and compute the maximum
 *        daily rainfall and the average daily rainfall.
 *    (b) Demonstrates use of one-dimensional arrays, and output to a file.
 * 
 *  Copyright (C) 1998 by Mark Austin and David Chancogne.
 *                                                                     
 *  This software is provided "as is" without express or implied warranty.
 *  Permission is granted to use this software on any computer system,
 *  and to redistribute it freely, subject to the following restrictions:
 * 
 *  1. The authors are not responsible for the consequences of use of
 *     this software, even if they arise from defects in the software.
 *  2. The origin of this software must not be misrepresented, either
 *     by explicit claim or by omission.
 *  3. Altered versions must be plainly marked as such, and must not
 *     be misrepresented as being the original software.
 *  4. This notice is to remain intact.
 * 
 *  Written by : Mark Austin 
 *  =======================================================================
 */

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

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

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

enum { MaxDays = 7 };

int main( void ) {
float faRainfall[ MaxDays ]; /* store the daily rainfall     */
float fSum = 0.0;            /* store sum of daily rainfalls */ 
float fMax = 0.0;            /* store maximum rainfall       */
float fAv  = 0.0;            /* store average rainfall       */
int iDay;                    /* day counter                  */

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

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

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

   for( iDay = 1; iDay <= MaxDays; iDay = iDay + 1 ) {
        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 = iDay + 1 )  {
        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 daily rainfall this week was %f inches\n", fAv );

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

   fileOut( faRainfall, fAv);
}

/*
 *  ====================================================================
 *  fileOut() : Write rainfall data to a file called RAIN.TXT
 *
 *  Input :  float faRainfall[] -- array of daily rainfall measurements.
 *           float fAv          -- average daily rainfalls for week.
 *  Output : void
 *  ====================================================================
 */

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

    FpRain = fopen("RAIN.TXT", "w");
    if(FpRain == NULL) {
       printf("ERROR >> File RAIN.TXT could not be opened\n");
       exit(1);
    }

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

    fclose( FpRain );
}