Array considered to be a pointer in the arguments - c

Question

I am trying to make a program where the user inserts the price of a certain item of his choice, then that price is stored in a list, and the user can expand that last as he wishes, but there is a problem, even though I have the exact same arguments and parameters, the array "prices" is considered to be a pointer for some reason.
#include <stdio.h>
void ask(char ques, int index, double prices[index], double price)
{
printf("Do you want to expand your list y/n: ");
scanf("%c", &ques);
printf("What do you want the price of the next item to be: ");
scanf("%lf", &price);
switch (ques)
{
case 'y':
prices[index + 1] = price;
case 'n':
main();
}
}
int main()
{
int index = -1;
double prices[index];
double price;
char ques;
ask(ques, index, prices[index], price);
}
I have this error: argument of type "double" is incompatible with parameter of type "double *"C

Answer 1

A solution using an array on the stack to store the prices.
prices.c
#include <stdio.h>
void ask(double prices[], int *elements, int max_elements)
{
if (*elements >= max_elements) {
printf("List is already full. (%d elements)\n", *elements);
return;
}
while (*elements < max_elements) // as long as there is space left
{
double price;
printf("What do you want the price of the next item to be: ");
scanf("%lf", &price);
prices[*elements] = price; // store price in array
*elements += 1; // increase number of elements
if (*elements == max_elements) {
printf("List is full. (%d elements)\n", max_elements);
break; // leave loop
}
char ques;
printf("Do you want to expand your list (y/n): ");
scanf(" %c", &ques);
if (ques == 'n') {
break; // leave loop
}
}
}
int main()
{
const int MAX_ELEMENTS = 10000; // 10000 prices should be enough for now
double prices[MAX_ELEMENTS]; // array to store 10000 prices
int elements = 0; // number of prices, currently none
ask(prices, &elements, MAX_ELEMENTS); // let user fill it
for (int i = 0; i < elements; i++) {
printf("%3d: %.2lf\n", i + 1, prices[i]); // print price number and price
}
return 0; // return 0 to indicate no error
}
Let's see how it works so far:
$ gcc -Wall prices.c
$ ./a.out
What do you want the price of the next item to be: 1.11
Do you want to expand your list (y/n): y
What do you want the price of the next item to be: 2.22
Do you want to expand your list (y/n): y
What do you want the price of the next item to be: 101
Do you want to expand your list (y/n): y
What do you want the price of the next item to be: 1000000.99
Do you want to expand your list (y/n): n
1: 1.11
2: 2.22
3: 101.00
4: 1000000.99
$
Test it online: https://onlinegdb.com/x1jVUU6GT