我所编的C语言程序编译的时候都是OK的 可是到了build的时候就出现错误了
2.obj : error LNK2005: "public: __thiscall Customer::Customer(void)" (??0Customer@@QAE@XZ) already defined in 1.obj
2.obj : error LNK2005: "public: virtual __thiscall Customer::~Customer(void)" (??1Customer@@UAE@XZ) already defined in 1.obj
2.obj : error LNK2005: "int i" (?i@@3HA) already defined in 1.obj
2.obj : error LNK2005: "struct Room * room" (?room@@3PAURoom@@A) already defined in 1.obj
2.obj : error LNK2005: "class Customer * * customer" (?customer@@3PAPAVCustomer@@A) already defined in 1.obj

应该是头文件定义的问题 求大神帮忙解决 谢谢了

头文件如下：

#include<iostream.h>
#include<string.h>

void initial_room();
void welcome();
void enter();
void book_room();
void check_in();
void check_out();
void inquire();

int i=0;

struct Room
{
 int number;
 int dank;
 int price;
 int state;
};
class Customer
{
public:
    Customer();
 void set_name(char *n) {strcpy(name,n);}
 void set_ID(char *p) {strcpy(ID,p);}
 void set_room_number(int n) {room_number=n;}
 void set_day(int d) {day=d;}
 void set_prepaid(int p) {prepaid=p;}
 char *get_name() {return name;}
 char *get_ID() {return ID;}
 int get_room_number() {return room_number;}
 int get_day() {return day;}
 int get_prepaid() {return prepaid;}
 virtual ~Customer();
private:
 char name[10],ID[19];
 int room_number;
 int prepaid;
 int change;
 int day;
};

Customer::Customer()

{
cout<<"请输入顾客的姓名\n";
cin>>name;
cout<<"请输入顾客的身份证号\n";
cin>>ID;
prepaid=change=day=0;
}

Customer::~Customer()  
{   
cout<<"该顾客退房成功!"<<endl;
 }

 Room room[80];
 Customer *customer[80];

有没有人帮忙呀~

目测是程序多次包含这个头文件 ， 引起了变量和类的重复定义

可是后面的函数里都要用这几个变量怎么办

可以使用条件编译将文件改写为
#ifndef HEAD_H
#define HEAD_H
   ...
class a
{
....
}
....
#endif
这个格式，可以防止被多次重复定义