浙大 PTA4-7

Stack CreateStack( int MaxSize ){Stack s=(Stack)malloc(sizeof(Stack));s->MaxSize=MaxSize;s->Top1=-1;s->Top2=MaxSize;s->Data=(ElementType*)malloc(sizeof(ElementType)*MaxSize);return s;}bool Push( Stack S, ElementType X, int Tag ){if(S==NULL)return false;if(S->Top1+1==S->Top2){printf("Stack Full\n");return false;}    if(Tag==1){S->Data[++(S->Top1)]=X;return true;}else if(Tag==2){S->Data[--(S->Top2)]=X;return true;}return false;}ElementType Pop( Stack S, int Tag ){if(S==NULL)return ERROR;if(Tag==1){if(S->Top1==-1){printf("Stack %d Empty\n",Tag);return ERROR;}return S->Data[(S->Top1)--];}else if(Tag==2){if(S->Top2==S->MaxSize){printf("Stack %d Empty\n",Tag);return ERROR;}return S->Data[(S->Top2)++];}return ERROR;}