请教c++程序

#include <stdio.h>
#include <stdlib.h>

typedef struct _Node{
int iValue;
_Node * pNext;
}NODE, *PNODE;

PNODE pHead;

void CreateList(void)
{
int *a; // 数组不可以定义成a[n],除非N是const型，或者被define过

PNODE pNewNode = NULL;
PNODE pWork = NULL;

pHead = (PNODE)malloc(sizeof(NODE));
if ( NULL == pHead )
{
printf("创建链表时发生错误!\n");
exit(-1);
}
pHead->iValue = 0;
pHead->pNext = NULL;
pWork = pHead;

for ( int i = 0 ; i <sizeof(a) ; i++ ) // I小于数组长度
{
pNewNode = (PNODE)malloc(sizeof(NODE));
if ( NULL == pNewNode )
{
printf("创建链表时发生错误!\n");
exit(-1);
}

pNewNode->iValue = a[i];
pNewNode->pNext = NULL;
pWork->pNext = pNewNode;
pWork = pNewNode;
}
}

void DestroyList(void)
{
PNODE pWork =