顺序栈的建立及操作

问题:建立顺序栈还是比较简单的。主要是一开始在入栈操作中每次调用初始化栈函数，结构出错。

代码：

#include <iostream>
#include <cstdlib>
using namespace std;
#define MAXSIZE 20
typedef struct SeqStack
{
	int stack [MAXSIZE];
	int top;
}*stackNode;

void initStack(stackNode &stack)
{
	stack=(stackNode)malloc(sizeof(struct SeqStack));
    if(!stack)
	{
		cout<<"allocate fail"<<endl;
		exit(EXIT_FAILURE);
	}
	else
	{
		stack->top=-1;
	}
}

void pushStack(stackNode stack,int elem)
{
	 if(stack->top==MAXSIZE)
	 {
		 cout<<"stack is full"<<endl;
		 exit(0);
	 }
	 else
	 {
		 stack->stack[++(stack->top)]=elem;
	 }
}

int  popStack(stackNode stack)
{
	int elem;
	if(stack->top==-1)
	{
		cout<<"栈已空"<<endl;
		return -1;
	}
	elem=stack->stack[stack->top];
	--stack->top;

	return elem;
}

int topStack(stackNode stack)
{
	int top;
	if(stack->top==-1)
	{
		cout<<"栈已空"<<endl;
		return -1;
	}
	top=stack->stack[stack->top];

	return top;
}

void showStack(stackNode stack)
{
	if(stack->top==-1)
	{
		cout<<"栈已空"<<endl;
		exit(-1);
	}
	while(stack->top!=-1)
	{
		cout<<stack->stack[stack->top]<<"--";
		--stack->top;
	}
	cout<<endl;
}

int main()
{
	stackNode stack=NULL;
	int top;
	int arr[]={1,3,5,6,7,2,9,8};
	initStack(stack);
	cout<<"入栈:"<<endl;
	for(int i=0;i<8;i++)
	{
		pushStack(stack,arr[i]);
	}

	top=topStack(stack);
	cout<<"top="<<top<<endl;

	cout<<"出栈元素为"<<popStack(stack)<<endl;
    cout<<"出栈元素为"<<popStack(stack)<<endl;

	cout<<"入栈:"<<endl;
	pushStack(stack,16);
	pushStack(stack,19);

	top=topStack(stack);
	cout<<"top="<<top<<endl;
	cout<<"遍历栈中的元素:";
	showStack(stack);
	return 0;
}

运行截图：