堆栈模拟队列

设已知有两个堆栈S1和S2，请用这两个堆栈模拟出一个队列Q。\

所谓用堆栈模拟队列，实际上就是通过调用堆栈的下列操作函数:\

• int IsFull(Stack S)：判断堆栈S是否已满，返回1或0；
• int IsEmpty (Stack S )：判断堆栈S是否为空，返回1或0；
• void Push(Stack S, ElementType item )：将元素item压入堆栈S；
• ElementType Pop(Stack S )：删除并返回S的栈顶元素。

实现队列的操作，即入队void AddQ(ElementType item)和出队ElementType DeleteQ()。

#include <stdlib.h>
struct stack
{
    int *data;
    int top;
    int maxsize;
};
typedef struct stack * Stack;

void InitStack(Stack &S, int n)
{
    S = (Stack)malloc(sizeof(struct stack));
    S->data = (int *)malloc( n * sizeof(int));
    S->top = -1;
    S->maxsize = n;
}
void push(Stack S, int item)
{
    S->top++;
    S->data[S->top] = item;
}

int pop(Stack S)
{
    return S->data[S->top--];
}

int IsFull(Stack S)
{
    if (S->top == S->maxsize - 1)
        return 1;
    else
        return 0;
}

int IsEmpty(Stack S)
{
    if (S->top == -1)
        return 1;
    else
        return 0;
}

void AddQ(int item, Stack S1, Stack S2)
{
    int n;
    if (IsFull(S1)==0)
    {
        push(S1, item);
    }
    else
    {
        if (IsEmpty(S2))
        {
            while (IsEmpty(S1) == 0)
            {
                n = pop(S1);
                push(S2, n);
            }
            push(S1, item);
        }
        else
        {
            printf("ERROR:Full\n");
        }
    }
}

void DeleteQ(Stack S1, Stack S2)
{
    /************** begin **************/
 

int n;
    if(!IsEmpty(S2)){
    	n=pop(S2);
	    printf("%d\n",n);
    }else if(IsEmpty(S2)&&!IsEmpty(S1)){
    	while(IsEmpty(S1)==0){
    		n=pop(S1);
    		push(S2,n);
		}
		printf("%d\n",pop(S2));
	}else if(IsEmpty(S1)&&IsEmpty(S2)){
		  printf("ERROR:Empty\n");
	}


    /**************  end  **************/
}

int main()
{
    int n1, n2;
    int num1, num2;
    scanf("%d %d", &num1, &num2);
    n1=num1<num2?num1:num2;
    n2=num1<num2?num2:num1;

    Stack S1,S2;
    InitStack(S1,n1);
    InitStack(S2,n2);

    char c;
    int d;
    scanf("%c", &c);
    while (c != 'T')
    {
        switch (c)
        {
        case 'A':
            scanf("%d", &d);
            AddQ(d, S1, S2);
            break;
        case 'D':
            DeleteQ(S1, S2);
            break;
        }
        scanf("%c", &c);
    }
    return 0;
}