实验2：函数重载、函数模板、简单类的定义和实现(实现多用户登录，注册，修改信息)
实验结论
重载函数add()
源码
这是按照给出的结构体 Complex并且没有使用函数模板写出的代码。
#include <iostream>
using namespace std;
typedef struct
{
double real;
double imaginary;
} Complex;
int add(int, int);
double add(double, double);
Complex add(Complex, Complex);
int main()
{
int a = 1, b = 5;
double x = 1.12, y = 5.36;
Complex m, n;
m.real = -12,m.imaginary=5;
n.real = -5,n.imaginary=2;
cout << add(a, b) << endl;
cout << add(x, y) << endl;
cout << add(m, n).real << "+" << add(m, n).imaginary <<"i"<< endl;
cin.get();
return 0;
}
int add(int a, int b)
{
return a + b;
}
double add(double a, double b)
{
return a + b;
}
Complex add(Complex a, Complex b)
{
Complex c;
c.real = a.real + b.real;
c.imaginary = a.imaginary + b.imaginary;
return c;
}
这是使用了C++自带的<complex>并且使用函数模板简化后的代码。
#include <complex>
#include <iostream>
using namespace std;
template <typename T>
T add(T a, T b)
{
return a + b;
}
int main()
{
int a = 1, b = 5;
double x = 1.12, y = 5.36;
complex<double> m{2.2, 5.4};
complex<double> n{3.5, 2.1};
cout << add(a, b) << endl;
cout << add(x, y) << endl;
cout << add(m, n).real() << "+" << add(m, n).imag() << "i" << endl;
cin.get();
return 0;
}
运行截图
因为除了测试数据有所不同，其他部分这两份代码的运行截图并无两样，故只给出一份
快速排序函数模板
实现了随机生成任意数量的整数和浮点数后，并排序。最后输出排序前后的整数和浮点数序列
源码
头文件 QuickSort.h
#ifndef _QUICKSORT_
#define _QUICKSORT_
#include <iomanip>
#include <iostream>
#include <vector>
using namespace std;
template <typename T>
void quick_sort(vector<T> &nums, int start, int end)
{
if (start >= end)
return;
T mid = nums[start];
int left = start, right = end;
while (left < right)
{
while (nums[right] >= mid && left < right)
right--;
while (nums[left] <= mid && left < right)
left++;
swap(nums[left], nums[right]);
}
swap(nums[left], nums[start]);
quick_sort(nums, start, left - 1);
quick_sort(nums, left + 1, end);
}
template <typename T>
void quick(vector<T> &nums)
{
quick_sort(nums, 0, nums.size() - 1);
}
template <typename T>
void output(vector<T> a)
{
int count = 0;
for (auto i : a)
{
count++;
cout << left << setw(5) << i << " ";
if (count == 10)
{
cout << endl;
count = 0;
}
}
cout << endl;
}
#endif
主函数
#include "QuickSort.h"
#include <ctime>
#include <iomanip>
#include <iostream>
#include <random>
#include <vector>
mt19937 gen(time(NULL));
uniform_int_distribution<> dis(1, 100);
uniform_real_distribution<> disf(1, 100);
void pause();
int main()
{
vector<int> nums;
vector<double> numsf;
int count;
cout << "How many numbers you want to generate randomly?" << endl;
cin >> count;
for (int i = 0; i < count; i++)
{
nums.push_back(dis(gen));
numsf.push_back(disf(gen));
}
cout << "int_unsorted:" << endl;
output(nums);
quick(nums);
cout << "int_sorted:" << endl;
output(nums);
cout << endl;
cout << setprecision(2) << setiosflags(ios::fixed);
cout << "double_unsorted:" << endl;
output(numsf);
cout << endl;
cout << "double_sorted:" << endl;
quick(numsf);
output(numsf);
pause();
return 0;
}
void pause()
{
cin.get();
cin.get();
}
运行截图
上图分别是生成40个数和20个数的运行截图。
用户类User
源码
头文件 User.h
#ifndef _USER_H
#define _USER_H
#include <conio.h>
#include <iostream>
#include <string>
using namespace std;
string input_star()
{
char password[30];
string passwd;
int index = 0;
while (1)
{
char ch;
ch = getch();
if (ch == 8)
{
if (index != 0)
{
cout << char(8) << " " << char(8);
index--;
}
}
else if (ch == '\r')
{
password[index] = '\0';
cout << endl;
break;
}
else
{
cout << "*";
password[index++] = ch;
}
}
passwd.assign(password);
return passwd;
}
class User
{
private:
string name = "";
string passwd = "111111";
string mail = "";
public:
User(string a, string b, string c) : name(a), passwd(b), mail(c){};
void SetPasswd()
{
string temp;
temp = input_star();
if (temp == "")
return;
passwd = temp;
}
void SetName()
{
string temp;
cin >> temp;
name = temp;
}
void SetMail()
{
string temp;
cin >> temp;
mail = temp;
}
string ReadName()
{
return name;
}
string ReadMail()
{
return mail;
}
string ReadPasswd()
{
return passwd;
}
void SetInfo()
{
cout << "Please enter the name:" << endl;
SetName();
cout << "Please enter the email:" << endl;
SetMail();
cout << "Please enter the password:" << endl;
SetPasswd();
}
void PrintInfo()
{
cout << "Name: " << name << endl;
cout << "Password: ******" << endl;
cout << "Mail: " << mail << endl;
}
};
#endif
主函数
//TODO:文件读写，实现软件关闭后打开依然可以登录
#include "User.h"
#include <iostream>
#include <string>
#include <vector>
using namespace std;
const User Default("", "111111", "");
vector<User> users;
char input;
string iemail, ipasswd, iname;
void Register();
void Login();
void Forget();
void Menu();
void LoginMenu();
int main()
{
while (1)
{
Menu();
cin >> input;
if (input == 'E')
break;
if (input == 'R')
{
Register();
}
if (input == 'L')
{
Login();
}
if (input == 'F')
{
Forget();
}
}
return 0;
}
void Menu()
{
cout << "Menu: R(egister),L(ogin),F(orget password),E(xit)" << endl;
}
void LoginMenu()
{
cout << "Menu: Change your P(assword) N(ame) E(mail). S(how info). Q(uit)" << endl;
}
void Register()
{
users.push_back(Default);
users.back().SetInfo();
while (1)
{
if (users.back().ReadMail().find('@') == string::npos)
{
cout << "The email you enter is wrong.Please enter again:" << endl;
users.back().SetMail();
}
else
break;
}
int temp = users.size();
for (int i = 0; i < temp - 1; i++)
{
if (users[i].ReadMail() == users.back().ReadMail() && users[i].ReadName() == users.back().ReadName())
{
users.pop_back();
cout << "Mail and name has been registered." << endl;
}
else if (users[i].ReadName() == users.back().ReadName())
{
users.pop_back();
cout << "The name has been registered." << endl;
}
else if (users[i].ReadMail() == users.back().ReadMail())
{
users.pop_back();
cout << "The mail has been registered." << endl;
}
}
}
void Login()
{
cout << "Please enter your email:" << endl;
cin >> iemail;
cout << "Please enter your password:" << endl;
ipasswd = input_star();
for (auto &i : users)
{
if (i.ReadMail() == iemail && ipasswd == i.ReadPasswd())
{
cout << "Login Sussfully" << endl;
while (1)
{
LoginMenu();
cin >> input;
if (input == 'Q')
break;
if (input == 'P')
{
cout << "Please enter your original password:" << endl;
ipasswd = input_star();
if (i.ReadPasswd() == ipasswd)
{
cout << "Please enter your new password:" << endl;
i.SetPasswd();
cout << "You have changed your password successfully.Please login again" << endl;
break;
}
else
{
cout << "Your original password is wrong!" << endl;
}
}
if (input == 'N')
{
cout << "Please enter your new name:" << endl;
i.SetName();
cout << "Change successfully!" << endl;
}
if (input == 'E')
{
cout << "Please enter your new mail:" << endl;
i.SetMail();
while (1)
{
if (i.ReadMail().find('@') == string::npos)
{
cout << "The email you enter is wrong.Please enter again:" << endl;
i.SetMail();
}
else
break;
}
cout << "Change successfully!" << endl;
}
if (input == 'S')
{
i.PrintInfo();
}
}
}
else
{
cout << "Login Fail!" << endl;
}
}
}
void Forget()
{
cout << "Please enter your email:" << endl;
cin >> iemail;
cout << "Please enter your name:" << endl;
cin >> iname;
if (users.size() == 0)
cout << "No match account" << endl;
else
{
for (auto i : users)
{
if (i.ReadMail() == iemail && i.ReadName() == iname)
{
cout << "Your password is\"" << i.ReadPasswd() << "\"" << endl;
}
else
{
cout << "No match account" << endl;
}
}
}
}
运行截图
因为实现的功能比较多，运行截图不能全部展示，建议自行编译运行查看。
实验总结与体会
-
体会到了重载函数使用的便利性，特别是可以使用函数模板进行整合的时候，代码会显得非常简洁凝练。
-
在设计
快速排序函数模板时，首次用到了vector，查阅了相当多的资料，比起C语言时的数组方便了好多用起来就一个字"爽"而且迭代器在我查阅的资料里被反复提及，没有去查是什么意思，当作一个注意点，之后可以去查查。 -
User类的实现花了我不少时间,虽然写出来的东西有那么一点点偏离题意？虽然输入文本时显示*是借鉴了网上的代码，但我还是进行了修改以实现复用。这个主函数基本实现了多用户的 注册，登录，忘记密码，修改信息 的系统。我给大家简单介绍一下实现的功能。-
用户注册时不能使用已经存在的用户名和邮箱。
-
需要输入密码的地方，输入内容显示星号。
-
同时输入正确的邮箱和用户名可以找回密码。这样不太安全，应该是给用户发邮件的，不过本来就是模拟登录流程，所以就这样啦。
-
邮箱正确性检测，含有@才可以通过。
-
登录后可以修改个人信息，修改密码需要正确输入原密码，且修改成功后需要重新登录。
-
可能有遗漏，毕竟写的时候也是想一出写一出。大家可以自行编译尝试。
-
TODO:文件读写，实现软件关闭后打开依然可以登录
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GeorgeWan
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