Thread: Heapify

I've tried to make a few different heapify functions, but none of them have worked. Why isn't this actually doing anything?

Code:

void heapify(int array[], int i) {
    int largest = 0;
    int temp = 0;
    int n = sizeof(array);
    int l = left(i);
    int r = right(i);
    if (l <= n && array[l] > array[i]) {
        cout << "\n\nHERE IS THE DAMN PROBLEM";
        largest = l;
    }
    else {
        cout << "\n\nOkay, the else statement is working.";
        largest = i;
    }
    if (r <= n && array[i] > array[largest]) {
        cout << "\n\nOkay, largest = r.";
        largest = r;
    }
    if (largest != i) {
        cout << "\n\nAlright, this got down to the last step.";
        temp = array[i];
        array[i] = array[largest];
        array[largest] = temp;
        heapify(array, largest);
    }

}

Thank you for all of the responses!

However, when I tried to do this the simplest way that I could (simply making n equal to the size of the array I'm testing for), it still doesn't do anything.
I've got it set up to make an array of random numbers between 1 and 99. Here's running it and printing the array before heapify:

Code:

***** WELCOME TO LINELL'S HEAP OF STUFF! *****     
Let me print the array of random numbers: 
39
35
5
2
89
48
27
66
70
61

Now I'll run the heapify and this should change the order to reflect the array becoming a heap. However, all I get for output is the exact same array.

Here it is in its entirety:

Code:

/*

    Linell 
    Due on 11/11/11 <- I'm totally getting Skyrim
               at 11:59 tonight.
 
*/
#include <iostream>
#include <cstdlib>
#include <time.h>
using namespace std;

    // The following functions will be used to make
    // and manipulate the heap.
int parent(int);
int left(int);
int right(int);
void heapify(int[], int);

int main() {
    int daheap[100];
    
    cout << "***** WELCOME TO LINELL'S HEAP OF STUFF! *****";
    cout << "     Let me print the array of random numbers: ";
    srand(time(NULL));
    for (int i = 0; i < 10; i++) {
        daheap[i] = rand() % 100;
    }
    for (int i = 0; i < 10; i++) {
        cout << endl << daheap[i];
    }
    
    heapify(daheap, 0);
    
    cout << "\n\n\n     Alright, now for daheap sorted! :) ";
    for (int i = 0; i < 10; i++) {
        cout << endl << daheap[i];
    }
    
    getchar();
}

    // Returns the parent of a certain node
int parent(int i) {
    return (i/2);
}
    // Returns the left child of a parent
int left(int i) {
    return (2*i);
}
    // Returns the right child of a parent
int right(int i) {
    return (2*i+1);
}
    // Heapifys an array
void heapify(int array[], int i) {
    int largest = 0;
    int temp = 0;
    int n = 10;
    int l = left(i);
    int r = right(i);
    if (l <= n && array[l] > array[i]) {
        cout << "\n\nHERE IS THE DAMN PROBLEM";
        largest = l;
    }
    else {
        cout << "\n\nOkay, the else statement is working.";
        largest = i;
    }
    if (r <= n && array[i] > array[largest]) {
        cout << "\n\nOkay, largest = r.";
        largest = r;
    }
    if (largest != i) {
        cout << "\n\nAlright, this got down to the last step.";
        temp = array[i];
        array[i] = array[largest];
        array[largest] = temp;
        heapify(array, largest);
    }

}

What should I pass through to it? I've tried passing a nine through, which should work, right? Same problem.