#define MaxSize /*存储数据元素的最大个数*/
typedef struct SNode *Stack;
struct SNode{ElementType Data[MaxSize];int Top;        //栈顶位置，即数组下标
};//1.入栈
void Push(Stack PtrS,ElementType item)
{if(PtrS->Top == MaxSize-1){printf(" 堆栈满 ");    return ;}else{PtrS-Data[++(PtrS->Top)] = item;return ;}
}//2.出栈
ElementType Pop(Stack PtrS)
{if(PtrS->Top == -1){printf(" 堆栈空 ");return ERROR;   /*ERROR是ElementType的特殊值，标志错误*/}elsereturn (PtrS->Data[(PtrS->Top)--]);
}

#define MaxSize     /*存储数据元素的最大个数*/
struct DStack{ElementType Data[MaxSize];int Top1;   /*堆栈1的栈顶指针*/int Top2;   /*堆栈2的栈顶指针*/
}S;
S.Top1 = -1;
S.Top2 = MaxSize;//入栈
void Push( struct DStack *PtrS,ElementType item,int Tag)
{/*Tag作为区分两个堆栈的标志，取值为1和2*/if( PtrS->Top2 - PtrS->Top1 == 1){  /*堆栈满*/printf("堆栈满");  return ;}if( Tag == 1)  /*对第一个堆栈操作*/PtrS->Data[++(PtrS->Top1)] = item;elsePtrS->Data[--(PtrS->Top2)] = item;
}//入栈
ElementType Pop( struct DStack *PtrS,int Tag)
{/*Tag作为区分两个堆栈的标志，取值为1和2 */if( Tag == 1){  /*对第一个堆栈操作*/if( PtrS->Top1 == -1){  /*堆栈1空*/printf(" 堆栈1空");    return NULL;}else {return PtrS->Data[(PtrS->Top1)--];}}else{if(PtrS->Top2 == MaxSize){  /*堆栈2空*/printf(" 堆栈2空 ");   return NULL;}else{return PtrS->Data[(PtrS->Top2)++];}}
}

typedef struct SNode *Stack;
struct SNode{ElementType Data;struct SNode *Next;
};//(1)堆栈初始化（建立空栈）
//(2)判断堆栈S是否为空//创建堆栈头结点
Stack CreateStack()
{/*构建一个堆栈的头结点，返回指针*/Stack S;S = (Stack)malloc(sizeof(struct SNode));S->Next = NULL;return S;
}//判断堆栈是否为空
int IsEmpty(Stack S)
{/*判断堆栈S是否为空，若为空函数返回整数1，否则返回0*/return ( S->Next == NULL);
}//入栈
void Push(ElementType item,Stack S)
{/*将元素item压入堆栈S*/struct SNode *TmpCell;TmpCell = (struct SNode *)malloc(sizeof(struct SNode));TmpCell->Element = item;TmpCell->Next = S->Next;S->Next = TmpCell;
}//判断数组满不满
ElementType Pop(Stack S)
{/*删除并返回堆栈s的栈顶元素*/struct SNode *FirstCell;ElementType TopElem;if( IsEmpty( S )){printf("堆栈空");  return NULL;}else{FirstCell = S->Next;S->Next = FirstCell->Next;TopElem = FirstCell->Element;free(FirstCell);return TopElem;}
}