C++，引发了异常: 读取访问权限冲突。

C++，引发了异常: 读取访问权限冲突。

调试时遇到的问题；

原代码

#include
#include
#include
using namespace std;
class car
{
	string chepaihao;
	double arrive_time;//到达的时间
public:
	time_t start, end;
	int zi_weizhi;//自己的位置
	car(string p);//到达时间赋0
	static int weizhi;//总共位置
	car* next;
	string REchepaihao();//返回车牌号
	void getchepai(string p);//赋值车牌号
	int left_time();
};
int car::weizhi = 0;

car* t_top;//另一个链表的头指针；
void reading(car*&);
void push(car*& top1, car* now)
{
	if (top1 == NULL)
	{
		top1 = now;
		top1->next = NULL;
	}
	else
	{
		now->next = top1;
		top1 = now;
	}
	//cout << now->REchepaihao() << "已进入停车位" << endl;
}
void pop(car*&top)
{
	car* p = top;
	top = top->next;
	delete p;
	cout <REchepaihao()<< "您已开出停车场或为他人让位"<next)
		cout << index->REchepaihao() << endl;
}
car::car(string p)
{
	chepaihao = p;
	weizhi++;
	zi_weizhi = weizhi;
	//double cost;
	time(&start);
	//sleep(1);
	//time(&end);
	//cost = difftime(end, start);
	//printf("%f/n", cost);
	arrive_time = 0;
	next = NULL;
}
string car::REchepaihao()
{
	return chepaihao;
}

void car::getchepai(string p)
{
	chepaihao = p;
}

int car::left_time()
{
	return 0;
}

void reading(car*&top)
{
	string a[2] = { "YOVGYC98","UIRBP09" };
	for (int i = 0;i < 2;i++)
	{
		car* index = new car(a[i]);
		push(top, index);//这里出了问题；
	}

}

问题出在未初始化头指针 调试时问题截图

加入

top = new car(“YUILKVG78”);

正确代码

#include
#include
#include
using namespace std;
class car
{
	string chepaihao;
	double arrive_time;//到达的时间
public:
	time_t start, end;
	int zi_weizhi;//自己的位置
	car(string p);//到达时间赋0
	static int weizhi;//总共位置
	car* next;
	string REchepaihao();//返回车牌号
	void getchepai(string p);//赋值车牌号
	int left_time();
};
int car::weizhi = 0;

car* t_top;//另一个链表的头指针；
void reading(car*&);
void push(car*& top1, car* now)
{
	if (top1 == NULL)
	{
		top1 = now;
		top1->next = NULL;
	}
	else
	{
		now->next = top1;
		top1 = now;
	}
	//cout << now->REchepaihao() << "已进入停车位" << endl;
}
void pop(car*&top)
{
	car* p = top;
	top = top->next;
	delete p;
	cout <REchepaihao()<< "您已开出停车场或为他人让位"<next)
		cout << index->REchepaihao() << endl;
}
car::car(string p)
{
	chepaihao = p;
	weizhi++;
	zi_weizhi = weizhi;
	//double cost;
	time(&start);
	//sleep(1);
	//time(&end);
	//cost = difftime(end, start);
	//printf("%f/n", cost);
	arrive_time = 0;
	next = NULL;
}
string car::REchepaihao()
{
	return chepaihao;
}

void car::getchepai(string p)
{
	chepaihao = p;
}

int car::left_time()
{
	return 0;
}

void reading(car*&top)
{
	top = new car("YUILKVG78");
	string a[2] = { "YOVGYC98","UIRBP09" };
	for (int i = 0;i < 2;i++)
	{
		car* index = new car(a[i]);
		push(top, index);
	}

}