Heap Sort Error: expression must be a pointer to a complete object type?

Question

I am implementing Heap Sort for an assignment. We have to do it the same way she did in class with her pseudocode, or else we dont get credit.

In my Max_Heapify function, im getting an error when I call my Left() and Right() functions, that say "expression must be a pointer to a complete object type". Im going directly off of psedocode, so im not sure what is causing this error, can anyone help?

void Max_Heapify(int heapArray[],int i)
{
int n = SIZE;
int largest = 0;
int l = Left[i];//<--Error here on Left
int r = Right[i];//<--Error here on Right

if(( l <= n) && (heapArray[l] > heapArray[i]))
{
    largest = l;
}
else
{
    largest = i;
}

if( (r <= n) && ( heapArray[r] > heapArray[largest]))
{
    largest = r;
}

int temp;
if(largest != i)
{
    temp = heapArray[i];
    heapArray[i] = heapArray[largest];
    heapArray[largest] = temp;

    Max_Heapify(heapArray,largest);
}

return;
}

...........................................................................................

Here are the Left() and Right() functions if it helps at all

int Left(int i)
{
return (2*i);
}

int Right(int i)
{
return ((2*i)+1);
}

Answer 1

Left & Right are functions; your code is using them as if they were arrays. To call a function, use (), not [].

Answer 2

You need Left(i) and Right(i), not Left[i] and Right[i]

Answer 3

int l = Left[i];//<--Error here on Left
int r = Right[i];//<--Error here on Right

int l = Left(i);//should be
int r = Right(i);//should be

Answer 4

it is an error because we use () to espress function call in C++. you have to change

int l = Left[i];

into

int l = Left(i);

Answer 5

If you want to see the best possible implementation of heapsort look into the linux kernel.

http://lxr.free-electrons.com/source/lib/sort.c

I remember staring at it when I was new to C so that I could absorb perfection.