/* sales.c */
#include <stdio.h>

int main(void) {

  const int MAX = 10;
  
  double singlePrice;
  int discountThreshold;
  double discountPercentage;
  double discountPrice;

  printf("Enter single price: ");
  scanf("%lf", &singlePrice);

  printf("Enter discount percentage: ");
  scanf("%lf", &discountPercentage);
  discountPrice = ( 1 - discountPercentage/100.0) * singlePrice;

  printf("Enter when discount starts: ");
  scanf("%d", &discountThreshold);

  printf("\n");

  double total=0.0;

  int i;
  for(i=1; i<=MAX; i++) {
    if(i<discountThreshold)
      total += singlePrice;
    else
      total += discountPrice;
    printf("%d items cost $%.2f\n", i, total);
  }

  printf("average price for %d items is $%.2f\n", MAX, total/MAX);

  return 0;
}