vector_int.hpp

#ifndef vector_int_hpp
#define vector_int_hpp
#include <cstdio>
#include <iostream>
using namespace std;
class Vector_int
{
private:
    int size;
    int *p;
public:
    
    int& at(int x){
        return p[x];
    }
    Vector_int(int size, int y = 0.0) : size(size)
    {
        cout << "Build a new class size = " << size << " , value = " << y << "\n";
        p = new int[size];
        for (int i = 0; i < size; ++i)
        {
            p[i] = y;
        }
    }
    Vector_int(const Vector_int &X)
    {
          cout << "Build a new class size = " << X.size << " , value = " << X.p[0] << "\n";
        p = new int[X.size];
        size = X.size;
        for (int i = 0; i < X.size; ++i)
        {
            p[i] = X.p[i];
        }
    }
    ~Vector_int()
    {
        cout << "Delete the class size = " << size << " , value = " << p[1] << "\n";
        delete[] p;
    }
};
#endif

task4.cpp

#include<iostream>
#include<cstdio>
#include"vector_int.hpp"
using namespace std;
int main()
{
    Vector_int x(10);
    puts("");
    Vector_int y(10,6);
    puts("");
    Vector_int z(y);
    puts("");
    y.at(0)=999;
    return 0;
}

Matrix.hpp

#ifndef Matrix_H
#define Matrix_H
#include <iostream>
using namespace std;
class Matrix
{
private:
    int lines, cols;
    double *p;

public:
    Matrix(int n)
    {
        lines = n, cols = n, p = new double[n * n];
    }
    Matrix(int n, int m)
    {
        lines = n, cols = m, p = new double[n * m];
    }
    Matrix(const Matrix &X)
    {
        lines = X.lines;
        cols = X.cols;
        p = new double[lines * cols];
        for (int i = 0; i < lines * cols; i++)
        {
            p[i] = X.p[i];
        }
    }
    ~Matrix()
    {
        delete[] p;
    }
    void set(const double *X)
    {
        for (int i = 0; i < lines * cols; i++)
        {
            p[i] = X[i];
        }
    };
    void set(int i, int j, int value)
    {
        if (i >= 0 && i < lines && j >= 0 && j < cols)
            p[i * cols + j] = value;
    }
    double &at(int i, int j)
    {
        if (i >= 0 && i < lines && j >= 0 && j < cols)
            return p[i * cols + j];
    };
    double at(int i, int j) const
    {
        if (i >= 0 && i < lines && j >= 0 && j < cols)
            return p[i * cols + j];
    };
    int get_lines() const
    {
        return lines;
    };
    int get_cols() const
    {
        return cols;
    };
    void print() const
    {
        for (int i = 0; i < lines; i++)
        {
            for (int j = 0; j < cols; j++)
            {
                cout << p[i * cols + j];
                if (j != cols - 1)
                {
                    cout << ", ";
                }
            }
            cout << "\n";
        }
    };
};
#endif

task5.cpp

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

int main()
{
    using namespace std;

    double x[] = { 7, 6, 5, 4, 3, 2};

    Matrix m1(3, 2);    // 创建一个3×2的矩阵
    m1.set(x);          // 用一维数组x的值按行为矩阵m1赋值
    m1.print();         // 打印矩阵m1的值
    cout << "the first line is: " << endl;
     cout << m1.at(0, 0) << " " << m1.at(0, 1) << endl;
    cout << endl;

    Matrix m2(2, 3);
    m2.set(x);
    m2.print();
    cout << "the first line is: " << endl;
 
     cout << m2.at(0, 0) << " " << m2.at(0, 1) << " " << m2.at(0, 2) << endl;
    cout << endl;

    Matrix m3(m2);
    m3.set(0,1, 123);
    m3.print();
}