实验6

任务4：

#pragma once
#include<iostream>
#include<stdexcept>

using namespace std;

template<typename T>
class Vector {
    private:
        int size;
        T* ptr;
    public:
        Vector(int n) {
            if (n < 0) {
                throw length_error("Vector constructor:negative size");
            } else {
                ptr = new T[size];
            }
        }

        Vector(int n, T value) {
            if (n < 0) {
                throw length_error("Vector constructor:negative size");
            } else {
                ptr = new T[size];
                for (int i = 0; i < size; i++) {
                    ptr[i] = value;

                }
            }
        }



        ~Vector(){delete[] ptr;}
        
        
        Vector(const Vector<T>& v){
    for (int i = 0; i < size; i++) {
        ptr[i] = v.ptr[i];
    }
}


        int get_size() {
            return size;
        }

        T& at(int index)const{
    if (index < 0 || index >= size) {
        throw out_of_range("Vector:index out of range");
    } else {
        return ptr[index];
    }
}

        T& at(int index);

        T& operator[](int index)const;
        T& operator[](int index) {
    return static_cast<const Vector*>(this)->at(index);

}

        template<typename T1>                                 
                friend void output(const Vector<T1>& v);
};


template<typename T>
T& Vector<T>::operator[](int index)const {
    if (index < 0 || index >= size) {
        throw out_of_range("Vector:index out of range");
    } else {
        return ptr[index];
    }

}
template<typename T>
T& Vector<T>::operator[](int index) {
    return static_cast<const Vector*>(this)->operator[](index);

}

template<typename T>
void output(const Vector<T>& v) {
    for (int i = 0; i < v.size; i++) {
        cout << v.ptr[i] << ", ";
    }
    cout <<"\b\b " << endl;

}

#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) { // 多组输入，按下Ctrl+Z终止
        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();
}

 

结果：

 

任务5：

#pragma once
#include<iostream>
#include<string>
#include<iomanip>

using namespace std;

class people
{
private:
    int id;
    string name;
    string major;
    int score;
public:
     people() = default;
    ~ people() = default;

    string get_major()const{
        return major;
    }
    int get_score()const{
        return score;
    }

    friend ostream& operator<<(ostream& out, people& p);
    friend istream& operator>>(istream& in, people& p);
};

ostream& operator<<(ostream& out,  people& p){
    out << setiosflags(ios_base::left);
    out << setw(10) << p.id
        << setw(10) << p.name
        << setw(10) << p.major
        << setw(10) << p.score << endl;
    return out;

}

istream& operator>>(istream& in, people& p){
    in >> p.id >> p.name >> p.major >> p.score;
    return in;
}

#pragma once
#include"people.hpp"
#include<iostream>
#include<string>
#include<fstream>
#include<vector>

bool paixu(const  people& p1, const  people& p2)
{
    if (p1.get_major() == p2.get_major()){
        return p1.get_score() > p2.get_score();
    }
    if (p1.get_major() < p2.get_major()){
        return true;
    }
    return false;
}

void output(ostream& out, const vector< people>& v)
{
    for (auto i : v){
        out << i;
    }
}

void save(const string& filename, vector< people>& v)
{
    ofstream out(filename);
    if (!out.is_open())
    {
        cout << "文件写入失败" << endl;
        exit(0);
    }
    output(out, v);
    out.close();
}

void load(const string& filename, vector< people>& v)
{
    string firstline;
     people p;
    ifstream in(filename);
    if (!in.is_open()){
        cout << "文件读出失败" << endl;
        exit(0);
    }

    getline(in, firstline);
    while (in >> p){
        v.push_back(p);
    }

    in.close();
}

#include"people.hpp"
#include"tools.hpp"
#include<string>
#include<vector>
#include<algorithm>
#include<iostream>

int main()
{
    vector< people> v;
    load("data5.txt", v);
    sort(v.begin(), v.end(), paixu);
    output(cout, v);
    save("ans.txt", v);
    return 0;
}

 

结果：