帮我看看这个堆排序代码哪错了？

C/C++ code

#define LEFT(i) (i << 1) + 1#define RIGHT(i) (i << 1) + 2#define PARENT(i) i >> iint heap_size;void heapify(int a[],int i){    int l = LEFT(i);    int r = RIGHT(i);    int largest;    if (l < heap_size && a[l] > a[i])        largest = l;    else        largest = i;    if (r < heap_size && a[r] > a[largest])        largest = r;    if (largest != i)    {        l = a[largest];        a[largest] = a[i];        a[i] = l;        heapify(a,largest);    }}void build_heap(int a[]){    heap_size = sizeof(a)/sizeof(int);    for (int i = heap_size / 2;i >= 0;--i)        heapify(a,i);}void heapsort(int a[]){    build_heap(a);    int t;    for (int i = sizeof(a)/sizeof(int) - 1;i >= 1;--i)    {        t = a[1];        a[1] = a[i];        a[i] = t;        --heap_size;        heapify(a,1);    }}

这是根据算法导论上写的，但是没效果。。。

[解决办法]
我的代码怎么被删了。我也在看这本书。

C/C++ code

#include <iostream>using namespace std;#define LEFT(i) ((((i+1) << 1)) - 1)#define RIGHT(i) (((i+1) << 1))#define PARENT(i) (((i+1) >> 1) - 1)int heap_size;void Exchange(int &a, int &b){    int temp = a;    a = b;    b = temp;}void MaxHeapify(int a[],int i){    int l = LEFT(i);    int r = RIGHT(i);    int largest = i;    if (l < heap_size && a[l] > a[i])        largest = l;    if (r < heap_size && a[r] > a[largest])        largest = r;    if (largest != i)    {        Exchange(a[i],a[largest]);        MaxHeapify(a,largest);    }}void BuildMaxHeap(int a[],int n){    //heap_size = sizeof(a)/sizeof(int);    heap_size = n;    for (int i = heap_size / 2;i >= 0;i--)        MaxHeapify(a,i);}void HeapSort(int a[],int n){    BuildMaxHeap(a,n);    for (int i = heap_size - 1; i >= 1; i--)    {        Exchange(a[0],a[i]);        --heap_size;        MaxHeapify(a,0);    }}int main(){    int a[5]={5,4,3,2,1}t