#include <iostream>
using namespace std;
struct complex {double real;double imaginary;
};
int add(int x2, int y2)
{return x2 + y2;
}
double add(double a1, double b1)
{return a1 + b1;
}
complex add(complex a, complex b)
{complex c;c.imaginary = a.imaginary + b.imaginary;c.real = a.real + b.real;return c;
}int add(int x2, int y2);
double add(double a1, double b1);
complex add(complex a, complex b);
int main()
{int x = 4, y = 3, s1;double m = 4.2, n =1.5, s2;complex complex1, complex2, complex3;complex1.real = 2, complex1.imaginary = 3;complex2.real = 6, complex2.imaginary = 4;s1 = add(x, y);s2 = add(m, n);complex3 = add(complex1, complex2);cout << s1 << endl;cout << s2 << endl;cout << complex3.real << "+" << complex3.imaginary << "i" << endl;system("pause");return 0;
}

#ifndef Quicksort
#define Quicksort
template <class T>
void quicksort(T s[], int low, int high) {int a, b, c = 0;T f, ex;a = low; b = high - 1; f = s[(low + high) / 2];if (a < b) {while (a < b) {while (a < b&&f < s[b])b--;while (a < b&&f > s[a])a++;if (a >= b) c = b;else { ex = s[a]; s[a] = s[b]; s[b] = ex; }}quicksort(s, low, c);quicksort(s, c + 1, high);}
}
#endif

#include <iostream>
#include <iomanip>
#include "quicksort.h"
using namespace std;
int main()
{int i;int a[5] = { 7,5,3,9,2 };double b[5] = { 5.5,8.5,9.9,2.5,3.6 };quicksort(a, 0, 5);quicksort(b, 0, 5);for (i=0;i<5;i++)cout << setw(5) << a[i];cout << endl;for (i=0;i<5;i++)cout << setw(5) << b[i];cout << endl;system("pause");return 0;
}

#include<iostream>
#include<string>
using namespace std;
class User {
public:User(string yourname, string yourpasswd, string youremail);User() {name = "";password = "111111";email = "";}void setInfo(string yourname = "", string yourpasswd = "111111", string youremail = "");void changePasswd();void printInfo();
private:string name;string password;string email;
};
void User::setInfo(string yourname, string yourpasswd, string youremail) {if (name == " ") cin >> yourname;name = yourname;    if (password == " ") cin >> yourpasswd;password = yourpasswd;if (email == " ") cin >> youremail;email = youremail;
}
void User::changePasswd() {string yourpassword;int i = 1;cout << "please input password:";cin >> yourpassword;while (password != yourpassword && i < 3){cout << "wrong,please input it again:";cin >> yourpassword;i++;}if (password != yourpassword && i == 3)cout << "please try later" << endl;if (password == yourpassword){cout << "please input your  password:";cin >> yourpassword;}
}
void User::printInfo() {cout << "Name: " << name << endl;cout << "Password: " << "******" << endl;cout << "Email: " << email << endl;
}

#include<iostream>
#include<iomanip>
#include"user.h"
int main() {cout << "testing 1......" << endl;User user1;user1.setInfo("Leonard");user1.printInfo();user1.changePasswd();user1.printInfo();cout << endl << "testing 2......" << endl << endl;User user2;user2.setInfo("Jonny", "92197", "xyz@hotmail.com");user2.printInfo();system("pause");return 0;
}