实验六

实验1

Complex.hpp

#pragma once

#include <iostream>
#include <stdexcept>

// 声明
////////////////////////////////////////////////////
// 复数模板类声明
template<typename T>
class Complex {
public:
Complex(T r = 0, T i = 0);
Complex(const Complex<T> &c);

T get_real() const;
T get_imag() const;

// 重载+=为成员函数
Complex<T>& operator+=(const Complex<T> &c);

// 重载<<、>>为友元函数
template<typename T1>
friend std::ostream& operator<<(std::ostream &out, const Complex<T1> &c);

template<typename T1>
friend std::istream& operator>>(std::istream &in, Complex<T1> &c);

private:
T real, imag;
};

// 普通函数声明
// 重载+用于Complex类型
template<typename T>
Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2);

// 重载==用于Complex类型
template<typename T>
bool operator==(const Complex<T> &c1, const Complex<T> &c2);

// 实现
////////////////////////////////////////////////////
// 成员函数模板实现
template<typename T>
Complex<T>::Complex(T r, T i): real{r}, imag{i} {
}

template<typename T>
Complex<T>::Complex(const Complex<T> &c): real{c.real}, imag{c.imag} {
}

template<typename T>
T Complex<T>::get_real() const {
return real;
}

template<typename T>
T Complex<T>::get_imag() const {
return imag;
}

// 重载+=为成员函数
template<typename T>
Complex<T>& Complex<T>::operator+=(const Complex<T> &c) {
real += c.real;
imag += c.imag;

return *this;
}

///////////////////////////////////////
// 友元函数模板实现
template<typename T1>
std::ostream& operator<<(std::ostream &out, const Complex<T1> &c) {
if(c.imag >= 0)
out << c.real << " + " << c.imag << "i";
else
out << c.real << " - " << -c.imag << "i";

return out;
}

template<typename T1>
std::istream& operator>>(std::istream &in, Complex<T1> &c) {
in >> c.real >> c.imag;

return in;
}

///////////////////////////////////////
// 普通函数模板实现
// 重载+用于Complex类型
template<typename T>
Complex<T> operator+(const Complex<T> &c1, const Complex<T> &c2) {
return Complex<T>(c1.get_real()+c2.get_real(),
c1.get_imag()+c2.get_imag());
}

// 重载==用于Complex类型
template<typename T>
bool operator==(const Complex<T> &c1, const Complex<T> &c2) {
return c1.get_real() == c2.get_real() &&
c1.get_imag() && c2.get_imag();
}

task1.cpp

#include "Complex.hpp"
#include <iostream>
#include <fstream>
#include <stdexcept>

void test1();
void test2();

int main() {
    using namespace std;

    cout << "测试1: 复数模板类测试" << endl;
    test1();

    cout << "\n测试2: 文件I/O测试" << endl;
    test2();
}

void test1() {
    using namespace std;

    Complex<double> c1{3.5, 2}, c2;
    cout << "Enter c2: ";
    cin >> c2;
    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;
    cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl;

    cout << "c1 + c2 = " << c1 + c2 << endl;
    c1 += c2;
    cout << "c1.real = " << c1.get_real() << endl;
    cout << "c1.imag = " << c1.get_imag() << endl;

    cout << "c1 == c2: " << boolalpha << (c1 == c2) << endl;
}

void test2() {
    using namespace std;

    Complex<int> c1{1, 2}, c2{9, -7};
    ofstream out("ans.txt");
    if(!out.is_open()) {
        cout << "fail to open file ans.txt to write\n";
        return;
    }

    out << "c1 = " << c1 << endl;
    out << "c2 = " << c2 << endl;
    out << "c1 + c2 = " << c1 + c2 << endl;
    out << "(c1 == c2) = " << boolalpha << (c1 == c2) << endl;

    out.close();
    cout << "测试ok!" << endl;
}

实验2

Contestant.hpp

#pragma once

#include <iostream>
#include <iomanip>
#include <string>

using std::string;
using std::ostream;
using std::istream;
using std::setw;
using std::setprecision;
using std::setiosflags;
using std::ios_base;

// Contestant类声明
class Contestant {
public:
    Contestant() = default;
    ~Contestant() = default;

    int get_num() const { return num; }
    float get_time_usage() const { return time_usage; }

    friend ostream& operator<<(ostream &out, const Contestant &c);
    friend istream& operator>>(istream &in, Contestant &c);

private:
    string no;          // 学号
    string name;        // 姓名
    string major;       // 专业
    int num;            // 解题数
    float time_usage;   // 总用时
};

// 友元函数实现
// 重载流插入运算符<<
ostream& operator<<(ostream &out, const Contestant &c) {
    out << setiosflags(ios_base::left);
    out << setw(15) << c.no
        << setw(15) << c.name
        << setw(15) << c.major
        << setw(5) << c.num
        << setprecision(2) << c.time_usage;
    
    return out;
}

// 重载流提取运算符>>
istream& operator>>(istream &in, Contestant &c) {
    in >> c.no >> c.name >> c.major >> c.num >> c.time_usage;

    return in;
}

utlis.hpp

#include "Contestant.hpp"
#include <fstream>
#include <iostream>
#include <string>
#include <vector>

// 排序函数
// 按解题数比较，解题数相同的情况下，按总用时比较，总用时越少，排名越靠前
bool compare_by_solutionInfo(const Contestant &c1, const Contestant &c2) {
    if(c1.get_num() > c2.get_num())
        return true;
    
    if(c1.get_num() == c2.get_num())
        return c1.get_time_usage() < c2.get_time_usage();
    
    return false;
}

// 把vector<Constestant>对象中的元素插入到输出流out
void output(std::ostream &out, const std::vector<Contestant> &v) {
    for(auto &i: v)
        out << i << std::endl;
}


// 把vector<Contestant>对象中的元素写到filename文件中
void save(const std::string &filename, std::vector<Contestant> &v) {
    using std::ofstream;

    ofstream out(filename);
    if(!out.is_open()) {
        std::cout << "fail to open file to write\n";
        return;
    }

    output(out, v);
    out.close();
}

// 从文件filename读取参赛选手信息到vector<Contestant>对象
void load(const std::string &filename, std::vector<Contestant> &v) {
    using std::ifstream;

    ifstream in(filename);
    if(!in.is_open()) {
        std::cout << "fail to open file to read\n";
        return;
    }

    std::string title_line;
    getline(in, title_line);     // 跳过标题行

    int first_column;
    Contestant t;
    while(in >> first_column >> t) 
        v.push_back(t);

    in.close();
}

task2.cpp

#include "Contestant.hpp"
#include "utils.hpp"
#include <iostream>
#include <vector>
#include <algorithm>


void test() {
    using namespace std;

    vector<Contestant> v;

    load("data2.txt", v);   // 从文件加载选手信息到对象v
    sort(v.begin(), v.end(), compare_by_solutionInfo);  // 按解题情况排序
    output(cout, v);    // 输出对象v中信息到屏幕
    save("ans.txt", v); // 把对象v中选手信息保存到文件
}

int main() {
    test();
}

实验3

Triangle.hpp

#include <iostream>
#include <stdexcept>
#include <cmath>

using namespace std;

class Triangle {
public:
    Triangle(double s1, double s2, double s3);
    ~Triangle() = default;

    double area() const;

private:
    double a, b, c;
};

Triangle::Triangle(double s1, double s2, double s3): a{s1}, b{s2}, c{s3} {
    if(a <= 0 || b <= 0 || c <= 0)
        throw invalid_argument("边长出现负值");
        
    if(a+b <= c || b+c <= a || a+c <= b) 
        throw invalid_argument("不满足任意两边之和大于第三边");
}

double Triangle::area() const {
    double s = (a + b + c)/2;
    return sqrt(s*(s-a)*(s-b)*(s-c));
}

task3.cpp

#include "Triangle.hpp"
#include <iostream>
#include <fstream>

void test() {
    using namespace std;

    cout << "从文件读入三角形三边边长，计算面积" << endl;

    ifstream in("data3.txt");
    if(!in.is_open()) {
        cout << "fail to open file to read\n";
        return;
    }

    double a,b,c;
    do {
        cout << "三角形边长: ";
        in >> a >> b >> c;
        cout << a << " " << b << " " << c << endl;

        try {
            Triangle t(a, b, c);
            cout << "三角形面积: " << t.area() << endl << endl;
        }catch(const exception &e) {
            cout << "error: " << e.what() << endl << endl;
        }

        if(in.peek() == EOF)
            break;
    } while(1);

    in.close();
}

int main() {
    test();
}

实验4

Vector.hpp

#pragma once

#include <iostream>
#include <stdexcept>

using namespace std;

template<typename T>
class Vector{
public:
    Vector(int n=0,T value=T())
    {
        size=n;
        if (size<0)
        throw std::length_error("Vector constructor:negative size");
    
        ptr=new T[size];
        
        for (int i=0;i<size;++i)
        {
            ptr[i]=value;
        }
        
    }
    Vector(const Vector<T>& other)
    {
        ptr=new T[size];
        
        for (int i=0;i<size;++i)
        {
            ptr[i]=other.ptr[i];
        }
    }
    ~Vector()
    {
        delete []ptr;
    }
    
public:
    int get_size() const
    {
        return size;
    }
    T& at(int index)
    {
        if (index<0||index>=size)
            throw std::out_of_range("Vector:index out of range");
        
        return ptr[index];
    }
    T& operator[](int index)
    {
        if (index<0||index>=size)
            throw std::out_of_range("Vector:index out of range");
        
        return ptr[index];
    }

public:
    friend std::ostream& operator<<(std::ostream& out,const Vector<T>& value)
    {
        for (int i=0;i<value.size-1;++i)
        {
            out<<value.ptr[i]<<",";
        }
        out<<value.ptr[value.size-1];
        return out;
    }
    friend void output(const Vector<T>& value)
    {
        std::cout<<value<<std::endl;
    }
private:
    int size;
    T* ptr;
};

task4.cpp

#include <iostream>
#include "Vector.hpp"

void test1() {
    using namespace std;

    int n;
    cout << "Enter n: ";
    cin >> n;
    
    Vector<double> x1(n);
    for(auto i = 0; i < n; ++i)
        x1.at(i) = i * 0.7;

    cout << "x1: "; output(x1);

    Vector<int> x2(n, 42);
    const Vector<int> x3(x2);

    cout << "x2: "; output(x2);
    cout << "x3: "; output(x3);

    x2.at(0) = 77;
    x2.at(1) = 777;
    cout << "x2: "; output(x2);
    cout << "x3: "; output(x3);
}

void test2() {
    using namespace std;

    int n, index;
    while(cout << "Enter n and index: ", cin >> n >> index) {
        try {
            Vector<int> v(n, n);
            v.at(index) = -999;
            cout << "v: "; output(v);
        }
        catch (const exception &e) {
            cout << e.what() << endl;
        }
    }
}

int main() {
    cout << "测试1: 模板类接口测试\n";
    test1();

    cout << "\n测试2: 模板类异常处理测试\n";
    test2();
}

实验5

Grade.hpp

#pragma once

#include <iostream>
#include <iomanip>
#include <string>

using std::string;
using std::ostream;
using std::istream;
using std::setw;
using std::setprecision;
using std::setiosflags;
using std::ios_base;

class Grade{
private:
    string no,name,major;
    int score;
public:
    Grade()=default;
    ~Grade()=default;
    
public:
    string get_no() const{return no;}
    string get_name() const{return name;}
    string get_major() const{return major;}
    int get_score() const{return score;}
    
public:
    friend ostream& operator<<(ostream &out, const Grade &g);
    friend istream& operator>>(istream &in, Grade &g);
};

ostream& operator<<(ostream &out, const Grade &g) {
    out << setiosflags(ios_base::left);
    out << setw(15) << g.no
        << setw(15) << g.name
        << setw(15) << g.major
        << setw(5) << g.score;
    return out;
}

istream& operator>>(istream &in, Grade &g) {
    in >> g.no >> g.name >> g.major >> g.score ;
    return in;
}

utils.hpp

#include "Grade.hpp"

#include <fstream>
#include <iostream>
#include <string>
#include <vector>

bool compare(const Grade &grade1,const Grade &grade2)
{
    if (grade1.get_major()<grade2.get_major()) return true;
    if (grade1.get_major()>grade2.get_major()) return false;
    return grade1.get_score()>grade2.get_score();
}

void output(std::ostream &out, const std::vector<Grade> &g) {
    for(auto &i: g)
        out << i << std::endl;
}

void save(const std::string &filename, std::vector<Grade> &g) {
    using std::ofstream;
    ofstream out(filename);
    if(!out.is_open()) {
        std::cout << "fail to open file to write\n";
        return;
    }
    output(out, g);
    out.close();
}

void load(const std::string &filename, std::vector<Grade> &g) {
    using std::ifstream;
    ifstream infile(filename);
    if(!infile.is_open()) {
        std::cout << "fail to open file to read\n";
        return;
    }
    std::string line;
    getline(infile, line); // 跳过标题行
    Grade t;
    while(infile >> t)
        g.push_back(t);
    infile.close();
}

task5.cpp

#include "Grade.hpp"
#include "utils.hpp"
#include <iostream>
#include <vector>
#include <algorithm>

void test() {
    using namespace std;
    vector<Grade> g;
    load("data5.txt", g); // 从文件加载选手信息到对象v
    sort(g.begin(), g.end(), compare); // 按解题情况排序
    output(cout, g); // 输出对象v中信息到屏幕
    save("ans5.txt", g); // 把对象v中选手信息保存到文件
}

int main() {
    test();
}