高手帮看一下 c++ 编程中的段错误
小弟是新手，在编一个银行用户的菜单时 于不断创建用户时，程序报段错误。其他功能完好，编译通过。自己反复察看无果，想请高手帮助，谢谢。
#include <iostream>
using namespace std;
//定义一个用户的类
class account{
private:
long id;
char* password;
double balance;
public:
account();//无参
~account();//析构
account(const account& accp);//拷贝构造函数
void app(); //申请动态空间
int create (char* pass,double balance); //创造 新的用户
int save(double sum); //存钱
int withdraw(char* pass,double sum); //取钱
double query(char* pass); //查询
account& operator=(const account& a); // 赋值重载
};
void create();
void save();
void with();
void query();
int c; //main 函数中 用户选择 几号菜单
int max_len=10; /* 设置 初始存放用户数组的空间 */
long i; //用于计数
double fsum;/* 区分 class 中的sum*/
char fpassword[50];
double fbalance;
long fid;
account* acc=new account[10]; //用acc 来存 用户信息
account::account(){
cout < < "hhhhhha " < <endl;
long id=0;
password = new char[50];
balance = 0;
}
account::account(const account& a){
password = new char[50];
id=a.id;
balance=a.balance;
strcpy(password,a.password);
}
account::~account(){
cout < < "delete " < <endl;
delete [] password;
}
int account::create (char* fpassword,double fbalance){
if((i+8)==max_len){
app();
}
balance=fbalance;
strcpy(password,fpassword);
cout < < "create " < <max_len < <endl;
cout < < "you win!!! new id " < <i < < " password: ";
cout < <password;
return 0;
}
int account::save(double sum){
balance=balance+sum;
cout < <id < < " acc saved money " < <sum < <endl;
return 0;
}
int account::withdraw(char* fpassword,double sum){
if(strcmp(password,fpassword)!=0){
return -1;
}
}
double account::query(char* fpassword){
if(strcmp(password,fpassword)==0){
return balance;
}
cout < < "wrong " < <endl;
return -1;
}
account& account::operator=(const account& a){
id=a.id;
balance=a.balance;
strcpy(password,a.password);
return *this;
}
void account:: app(){
account* str=new account[max_len+10];
cout < < "gagagagagagaga " < <endl;
for(int i=0;i <max_len;i++){
str[i]=acc[i];
}
delete []acc;
acc=str;
max_len=max_len+10;
str=NULL;
delete [] str;
cout < <max_len < < "app " < <endl;
}
void create(){
cin> > fpassword;
cin> > fbalance;
acc[i].create(fpassword,fbalance);
i++;
}
void save(){
cin> > fid;
cin> > fsum;
acc[fid].save(fsum);
}
void with(){
cin> > fid;
cin> > fpassword;
cin> > fsum;
int ret=acc[fid].withdraw(fpassword,fsum);
if(ret==0){
cout < <fid < < " acc withdrawed money " < <fsum < <endl;
}
if(ret==-1){
cout < < "id or password wrong " < <endl;
}
}
void query(){
cin> > fid;
cin> > fpassword;
double ret=acc[fid].query(fpassword);
if(ret==-1){
cout < < "id or password wrong " < <endl;
}
cout < <fid < < " acc have " < <ret < <endl;
}
int menu(int c){
switch (c){
case 1:{
if(c==1){
cout < < "========== " < <endl;
cout < < "enter your password and money \n ";
cout < < "========== " < <endl;
create();
break;
}
}
case 2:{
if(c==2){
cout < < "========== " < <endl;
cout < < "enter your Id and money \n ";
cout < < "========== " < <endl;
save();
break;
}
}
case 3:{
if(c==3){
cout < < "========== " < <endl;
cout < < "enter your Id password sum \n ";
cout < < "========== " < <endl;
with();
break;
}
}
case 4:{
if(c==4){
cout < < "========== " < <endl;
cout < < "enter your Id and password \n ";
cout < < "========== " < <endl;
query();
break;
}
}
case 5:{
if(c==5){
cout < < "bye \n ";
break;
}
}
}
}
int main(){
while(c!=5){
cout < < "========== " < <endl;
cout < < "1 ------> create " < <endl;
cout < < "2 --------> save " < <endl;
cout < < "3 ----> withdraw " < <endl;
cout < < "4 -------> query " < <endl;
cout < < "5 --------> back " < <endl;
cout < < "========== " < <endl;
cout < < "enter the num " < <endl;
cin> > c;
if(!cin){
cout < < "gaga \n ";
break;
}
menu(c);
}
return 0;
}
[解决办法]
#include <iostream>
using namespace std;
//定义一个用户的类
class account{
private:
long id;
char* password;
double balance;
public:
account();//无参
~account();//析构
account(const account& accp);//拷贝构造函数
//去掉
//void app(); //申请动态空间
int create (char* pass,double balance); //创造 新的用户
int save(double sum); //存钱
int withdraw(char* pass,double sum); //取钱
double query(char* pass); //查询
account& operator=(const account& a); // 赋值重载
};
void create();
void save();
void with();
void query();
int c; //main 函数中 用户选择 几号菜单
int max_len=10; /* 设置 初始存放用户数组的空间 */
long i; //用于计数
double fsum;/* 区分 class 中的sum*/
char fpassword[50];
double fbalance;
long fid;
account* acc=new account[10]; //用acc 来存 用户信息
account::account(){
cout < < "hhhhhha " < <endl;
long id=0;
password = new char[50];
balance = 0;
}
account::account(const account& a){
password = new char[50];
id=a.id;
balance=a.balance;
strcpy(password,a.password);
}
account::~account(){
cout < < "delete " < <endl;
delete [] password;
password = NULL;
}
int account::create (char* fpassword,double fbalance){
//这里要去掉
//if((i+8)==max_len){
//app();
//}
balance=fbalance;
strcpy(password,fpassword);
cout < < "create " < <max_len < <endl;
cout < < "you win!!! new id " < <i < < " password: ";
cout < <password;
return 0;
}
int account::save(double sum){
balance=balance+sum;
cout < <id < < " acc saved money " < <sum < <endl;
return 0;
}
int account::withdraw(char* fpassword,double sum){
if(strcmp(password,fpassword)!=0){
return -1;
}
}
double account::query(char* fpassword){
if(strcmp(password,fpassword)==0){
return balance;
}
cout < < "wrong " < <endl;
return -1;
}
account& account::operator=(const account& a){
//这里修改了，，不是 *this == a
if(this==&a) return *this;
delete [] password;
id=a.id;
balance=a.balance;
password=new char[50];
strcpy(password,a.password);
return *this;
}
//这里修改了，变为全局函数
void app(){
account* str=new account[max_len+10];
cout < < "gagagagagagaga " < <endl;
for(int x=0; x <i; x++){
str[x]=acc[x];
}
delete []acc;
acc=str;
max_len=max_len+10;
cout < <max_len < < "app " < <endl;
}
void create(){
cin> > fpassword;
cin> > fbalance;
//这里修改了，改为每输入10个就重新自动分配一次内存，自动调整帐号数量大小
if ( i == max_len)
{
app();
}
acc[i].create(fpassword,fbalance);
i++;
}
void save(){
cin> > fid;
cin> > fsum;
acc[fid].save(fsum);
}
void with(){
cin> > fid;
cin> > fpassword;
cin> > fsum;
int ret=acc[fid].withdraw(fpassword,fsum);
if(ret==0){
cout < <fid < < " acc withdrawed money " < <fsum < <endl;
}
if(ret==-1){
cout < < "id or password wrong " < <endl;
}
}
void query(){
cin> > fid;
cin> > fpassword;
double ret=acc[fid].query(fpassword);
if(ret==-1){
cout < < "id or password wrong " < <endl;
}
cout < <fid < < " acc have " < <ret < <endl;
}
int menu(int c){
switch (c){
case 1:{
if(c==1){
cout < < "========== " < <endl;
cout < < "enter your password and money \n ";
cout < < "========== " < <endl;
create();
break;
}
}
case 2:{
if(c==2){
cout < < "========== " < <endl;
cout < < "enter your Id and money \n ";
cout < < "========== " < <endl;
save();
break;
}
}
case 3:{
if(c==3){
cout < < "========== " < <endl;
cout < < "enter your Id password sum \n ";
cout < < "========== " < <endl;
with();
break;
}
}
case 4:{
if(c==4){
cout < < "========== " < <endl;
cout < < "enter your Id and password \n ";
cout < < "========== " < <endl;
query();
break;
}
}
case 5:{
if(c==5){
cout < < "bye \n ";
break;
}
}
}
}
int main(){
while(c!=5){
cout < < "========== " < <endl;
cout < < "1 ------> create " < <endl;
cout < < "2 --------> save " < <endl;
cout < < "3 ----> withdraw " < <endl;
cout < < "4 -------> query " < <endl;
cout < < "5 --------> back " < <endl;
cout < < "========== " < <endl;
cout < < "enter the num " < <endl;
cin> > c;
if(!cin){
cout < < "gaga \n ";
break;
}
menu(c);
}
return 0;
}
我重新把整个程序给修改了,这个在void create() 实现了自动调整帐号大小的功能
