Heap and Heap sort

The following is the code of basic heap operations and heap sort.

//Here is the header file myHeap.h


#ifndef MYHEAP_H
#define MYHEAP_H
class myHeap{
int heapSize;
public:
int parent(int i){
return i/2;
}

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

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

void maxHeapify(int *A, int i);
void makeHeap(int *A, int size);
void myHeapSort(int *A, int size);
};

#endif

//Here is the source file myHeap.cpp


#include "myHeap.h"
void myHeap::maxHeapify(int *A, int i){
int l=left(i);
int r=right(i);
int temp=0;
int large;

if(l<=heapSize && A[l-1]>A[i-1]){
 large=l;
}
else
 large=i;

if(r<=heapSize && A[r-1]>A[large-1]){
 large=r;
}

if(large!=i){
temp=A[i-1];
A[i-1]=A[large-1];
A[large-1]=temp;
maxHeapify(A, large);
}

}

void myHeap::makeHeap(int *A, int size){
heapSize=size;
for(int i=heapSize/2; i>0; i--)
 maxHeapify(A,i);

}

void myHeap::myHeapSort(int *A, int size){
makeHeap(A,size);
for(int i=heapSize;i>1;i--){
int temp=A[0];
A[0]=A[i-1];
A[i-1]=temp;
heapSize--;
maxHeapify(A,1);
}
}

Things need to pay close attention to when designing the heap code:

1) The index of an array begins from zero. The index of a heap tree begins from one.

2) The use of "large" in maxHeapify is quite beautiful. You need to first compare A[l] with A[i] and assign the larger one to large. Then compare A[r] and A[large].