/* sales: Greatest sales of three consecutive months

   Example:

	Enter 1. value: 2
	Enter 2. value: 2
	Enter 3. value: 2
	Enter 4. value: 2
	Enter 5. value: 4
	Enter 6. value: 6
	Enter 7. value: 2
	Enter 8. value: 2
	Enter 9. value: 2
	Enter 10. value: 2
	Enter 11. value: 2
	Enter 12. value: 2
	Total sales 30.
	Greatest three month sales was 12
*/

#include <stdio.h>

int monthsToProcess, currentMonth,		/* Month          */
    INT_current, previous, preceding,		/* Monthly values */
    INT_greatest, total;			/* Results        */

int main (void) {

    printf("Enter 1. value: "); scanf("%d", &preceding);
    printf("Enter 2. value: "); scanf("%d", &previous);
    printf("Enter 3. value: "); scanf("%d", &INT_current);
    total = INT_current + previous + preceding;
    INT_greatest = total;
    monthsToProcess = 12;

    for (currentMonth = 4; currentMonth <= monthsToProcess;
         currentMonth += 1) {
        preceding = previous;
        previous = INT_current;
        printf("Enter %d. value: ", currentMonth);
	scanf("%d", &INT_current);
	total += INT_current;
        if (INT_current + previous + preceding > INT_greatest)
	    INT_greatest = INT_current + previous + preceding;
    }

    printf("Total sales %d.\nGreatest three month sales was %d\n",
           total, INT_greatest);

   return(0);
}

   	Modify the above program not to look for three months sales
   	but three months average sales so that the middle month has
        double the weight of the other two months (e.g., if the
        sales figures for three consecutive months are 1, 7, and 5,
        the weighted average is (1+7+7+5) / 4 = 5).