Question

typedef double (*price_fn)(void* obj);
typedef double (*bulk_price_fn)(void* obj, unsigned int quantity);

// Compares the price of obj1 with obj2
// Returns a negative number if the price of obj1 is less than the price of obj2
// Returns a positive number if the price of obj1 is greater than the price of obj2
// Returns 0 if the price of obj1 is equal to the price of obj2
int compare_by_price(Object* obj1, Object* obj2)
{
   // IMPLEMENT THIS
   return 0;
  
}

// Compares the quantity of obj1 with obj2
// Returns a negative number if the quantity of obj1 is less than the quantity of obj2
// Returns a positive number if the quantity of obj1 is greater than the quantity of obj2
// Returns 0 if the quantity of obj1 is equal to the quantity of obj2
int compare_by_quantity(Object* obj1, Object* obj2)
{

}

- We are not allowed to use any libraries besides the math.h

- This is C programming language

Answer 1

typedef double (*price_fn)(void* obj);
typedef double (*bulk_price_fn)(void* obj, unsigned int quantity);

// Compares the price of obj1 with obj2
// Returns a negative number if the price of obj1 is less than the price of obj2
// Returns a positive number if the price of obj1 is greater than the price of obj2
// Returns 0 if the price of obj1 is equal to the price of obj2
int compare_by_price(Object* obj1, Object* obj2)
{
   return (*price_fn)(obj1->price) - (*price_fn)(obj2->price);  
}

// Compares the quantity of obj1 with obj2
// Returns a negative number if the quantity of obj1 is less than the quantity of obj2
// Returns a positive number if the quantity of obj1 is greater than the quantity of obj2
// Returns 0 if the quantity of obj1 is equal to the quantity of obj2
int compare_by_quantity(Object* obj1, Object* obj2)
{
   return obj1->quantity - obj2->quantity;  
}

************************************************** You have not shared the schema of Object structure.. I am assuming that it has members for Price and Quantity.. Also, There does not seem any function for comparing the quantity.. Hence, i have directly compared the quantity, assuming they are integers. Thanks for your question. We try our best to help you with detailed answers, But in any case, if you need any modification or have a query/issue with respect to above answer, Please ask that in the comment section. We will surely try to address your query ASAP and resolve the issue.

Please consider providing a thumbs up to this question if it helps you. by Doing that, You will help other students, who are facing similar issue.