c++实验6

实验任务4

#include<iostream>
#include<stdexcept>
template<typename T>
class Vector{
private:
    T* data;
    int num;
public:
    Vector(int size);
    Vector(int size,const T& value); 
    Vector(const Vector<T>& other); 
    ~Vector();
    int get_size()const; 
    T& at(int index); 
    const T& at(int index)const; 
    T& operator[](int index);
    const T& operator[](int index)const;        
};
template<typename T>
Vector<T>::Vector(int size){
    if(size<0){
        throw std::length_error("Vectro constructor:negative size");
    }
    num=size;
    data=new T[num];
}
template<typename T>
Vector<T>::Vector(int size,const T&value){
    if(size<0){
        throw std::length_error("Vector constructor:negative size");
    }
    num=size;
    data=new T[num];
    for(int i=0;i<num;++i){
        data[i]=value;
    }
}
template<typename T>
Vector<T>::Vector(const Vector<T>& other){
    num=other.num;
    data=new T[num];
    for(int i=0;i<num;++i){
        data[i]=other.data[i];
    }
}
template<typename T>
Vector<T>::~Vector(){
    delete[] data;
}
template<typename T>
int Vector<T>::get_size()const{
    return num;
}
template<typename T>
T& Vector<T>::at(int index){
    if(index>=num){
        throw std::out_of_range("Vector:index out of range");
    }
    return data[index];
} 
template<typename T>
const T&Vector<T>::at(int index)const{
    if(index>=num){
        throw std::out_of_range("Vector:Index out of range");
    }
    return data[index];
}
template<typename T>
T& Vector<T>::operator[](int index){
    if(index>=num){
        throw std::out_of_range("Vector:Index out of range");
    }
    return data[index];
}
template<typename T>
const T& Vector<T>::operator[](int index)const{
    if(index>=num){
        throw std::out_of_range("Vector:Index out of range");
    }
    return data[index];
} 
template<typename T>
std::ostream& operator<<(std::ostream& os,const Vector<T>& v){
    for(int i=0;i<v.get_size();++i){
        os<<v[i];
        if(i<v.get_size()-1){
            os<<", ";
        }
    }
    return os;
}
template<typename T>
void output(const Vector<T>& v){
    std::cout<<v<<std::endl;
}

 

 

实验任务5

 

#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
#include <algorithm>
#include <string>
#include <tuple>

struct Student {
    int id;
    std::string name;
    std::string major;
    int score;
};

bool compareStudents(const Student& a, const Student& b) {
    if (a.major < b.major) return true;
    else if (a.major == b.major && a.score > b.score) return true;
    return false;
}
int main() {
    std::vector<Student> students;
    std::ifstream inputFile("D:\\c++\\printf()的用法\\printf()的用法\\data5.txt");
    if (!inputFile) {
        std::cerr << "无法打开输入文件" << std::endl;
        return -1;
    }
    std::string line;
    std::getline(inputFile, line);
    while (std::getline(inputFile, line)) {
        std::istringstream iss(line);
        Student student;
        iss >> student.id >> student.name >> student.major >> student.score;
        students.push_back(student);
    }
    inputFile.close();
    std::sort(students.begin(), students.end(), compareStudents);
    std::ofstream outputFile("D:\\c++\\printf()的用法\\printf()的用法\\ans5.txt");
    if (!outputFile) {
        std::cerr << "无法打开输出文件" << std::endl;
        return -1;
    }
    outputFile << "学号\t姓名\t专业\t分数\n";
    for (const auto& student : students) {
        std::cout << student.id << '\t' << student.name << '\t' << student.major << '\t' << student.score << '\n';
        outputFile << student.id << '\t' << student.name << '\t' << student.major << '\t' << student.score << '\n';
    }
    outputFile.close();
    return 0;
}