#define MaxSize 50             //定义栈中元素的最大个数
typedef struct{Elemtype data[MaxSize]; //存放栈中元素
}Sqstack;                      //顺序栈简写

bool StackEmpty(SqStack S){if(S.top==-1) return true;else               return false;
}

bool Push(SqStack &S,Elemtype x){if(S.top==MaxSize-1) return false;S.data[++S.top]=x; return true;
}

bool Pop(SqStack &S,Elemtype &x){if(S.top==-1) return false;x=S.data[S.top--]; return true;
}

bool GetTop(SqStack S,Elemtype &x){if(S.top==-1) return false;x=S.data[S.top];return true;
}

#define MaxSize 100            //定义栈中元素的最大个数
typedef struct{Elemtype data[MaxSize]; //存放栈中元素int top1;int top2;
}SqDoublestack;               //顺序共享栈简写

bool Push(SqDoubleStack &S,ElemType x,int stackNum0{if(S.top1+1=S.top2) return false;if(stackNum==1) S.data[++S.top1]=x;//栈1有元素进栈if(stackNum==2) S.data[++S.top2]=x;//栈2有元素进栈return true;
}

typedef struct SNode{ElemType data;      //存放栈中元素struct SNode *next; //栈顶指针
}SNode *SLink               //链栈的结点

typedef struct LinkStack{SLink top;    //栈顶指针int count;    //链栈结点数
}LinkStack                 //链栈

bool Push(LinkStack &S,ElemType x){SLink p=(SLink)mallo((sizeof(SNode));//给新元素分配空间p->data=x;                           //新元素的值p->next=s->top;                      //p的后继指针指向新的元素s->top=p;                            //栈顶指针指向新的元素s->count++;                          //栈中元素加1return true;
}

bool Pop(LinkStack &S, ElemType &x){if(S->top==NULL) return false;x=S->top->data;          //栈顶元素值Slink p=S->top;          //辅助指针S->top=S->top->next;     //栈顶指针后移free(p);                 //释放被删除数据的存储空间S->count--;  栈中元素个数减1return true;
}