HeapSort Algorithm Source Code in C++

/*
 * HeapSort.cpp
 *
 *  Created on: 13 Ara 2011
 *      Author: blog.asosyalbebe.com
 */
#include <iostream>
#include <stdlib.h>

using namespace std;

void heapsort(int array[], int size);
void buildheap(int array[], int size);
void percolateDown(int heap[], int size, int id);

void printArray(int array[], int size) {
    for(int i=0; i<size; i++) {
        cout << array[i] << " ";
    }
    cout << endl;
}

int main() {
    int size = 20;
    int arrayToSort[size];
    for(int i=0; i<size; i++)
        arrayToSort[i] = 1+rand()%99; // between 1 and 99
    printArray(arrayToSort, size);

    heapsort(arrayToSort, size);

    printArray(arrayToSort, size);
}

void heapsort(int array[], int size) {
    buildheap(array, size);
    int heapsize = size;

    for(int i=size-1; i>0; i--) {
        int temp = array[i];
        array[i] = array[0];
        array[0] = temp;
        heapsize--;
        percolateDown(array, heapsize, 0);
    }
}

void buildheap(int array[], int size) {
    for(int i=size/2; i>=0; i--) {
        percolateDown(array, size, i);
    }
}

void percolateDown(int array[], int size, int id) {
    int current = id;
    int max;
    while(true) {
        int left = current*2+1;
        int right = current*2+2;
        if(left >= size)
            return;
        else if(right >= size)
            max = left;
        else if(array[left] > array[right])
            max = left;
        else if(array[left] < array[right])
            max = right;
        if(array[max] > array[current]) {
            int temp = array[max];
            array[max] = array[current];
            array[current] = temp;
            current = max;
        } else
            return;
    }
}