链表：
pHead = （( pStu ) malloc( sizeof( Stu ) )
pHead->pNext = NULL
pTail = pHead
pNew =（( pStu ) malloc( sizeof( Stu ) )
pTail->pNext = pNew
pNew->pNext = NULL
pTail = pNew
栈：
pStack->pTop = ( pNODE ) malloc( sizeof ( NODE ) )
pStack->pButton = pStack->pTop
pNODE pNew = ( pNODE ) malloc( sizeof ( NODE ) )
pNew->date = val
pNew->pNext = pStack->pTop
pStack->pTop = pNew
