实验三

task4.hpp

#pragma once
#ifndef VECTOR_INT_HPP
#define VECTOR_INT_HPP
#include<iostream>

class vector_int
{
private:
    int* p;
    int size;
public:
    vector_int(int numble, int val);
    vector_int(const vector_int& a1);
    ~vector_int();
    void show();
    int& at(int index);
};

vector_int::vector_int(int numble,int val=0) {

    using namespace std;
    size = numble;
    p = new int[size];
    for (int i = 0; i < size; i++) {
        p[i] = val;
    }
    cout << "calling the constructor" << endl;
}

vector_int::vector_int(const vector_int& a1) {
    using namespace std;
    size = a1.size;
    p = new int[size];
    for (int i = 0; i < size; i++) {
        p[i] = a1.p[i];
    }
    cout << "calling the copy constructor" << endl;
}

vector_int::~vector_int() {
    using namespace std;
    delete[] p;
    cout << "destroy the constructor" << endl;
}

void vector_int::show() {

    using namespace std;
    for (int i = 0; i < size; i++) {
           cout << p[i] << ", ";
    }
    cout << endl;
    
}

int& vector_int::at(int index) {
    if (index > 0 && index < size)
        return p[index];

}

#endif

task4.cpp

#include "vector_int.hpp"

int main() {
    using namespace std;
    int n=10;
    vector_int x(n);
    x.show();
    vector_int z(n, 6);
    z.show();
    vector_int y(x);
    y.show();
    y.at(0) = 999;
    y.show();
}

 

运行截图：

 

 

 

task6.hpp

#ifndef MATRIX_H
#define MATRIX_H

#include <iostream>
#include <cassert>

class Matrix
{
public:
    Matrix(int n);                     // 构造函数，构造一个n*n的矩阵
    Matrix(int n, int m);              // 构造函数，构造一个n*m的矩阵
    Matrix(const Matrix &X);           // 复制构造函数，使用已有的矩阵X构造
    ~Matrix();                         //析构函数
    void set(const double *pvalue);     // 用pvalue指向的连续内存块数据为矩阵赋值
    void set(int i, int j, double value); //设置矩阵第i行第j列元素值为value
    double &at(int i, int j);          //返回矩阵第i行第j列元素的引用
    double at(int i, int j) const;     // 返回矩阵第i行第j列元素的值
    int get_lines() const;             //返回矩阵行数
    int get_cols() const;              //返回矩列数
    void print() const;                // 按行打印输出矩阵
private:
    int lines; // 矩阵行数
    int cols;  // 矩阵列数
    double *p; // 指向存放矩阵数据的内存块的首地址
};


// 类Matrix的实现：待补足
// ×××
Matrix::Matrix(int n): lines(n), cols(n)
{
    this->p = new double[this->lines * this->cols];
}
Matrix::Matrix(int n, int m): lines(n), cols(m)
{
    this->p = new double[this->lines * this->cols];
}
Matrix::Matrix(const Matrix &X): lines(X.lines), cols(X.cols)
{
    this->p = new double[this->lines * this->cols];
    for (int i = 0; i < this->lines * this->cols; i++)
        p[i] = X.p[i];
}
Matrix::~Matrix()
{
    delete[] this->p;
    this->p = nullptr;
}
void Matrix::set(const double *pvalue)
{
    int tail = 0;
    for (int i = 0; i < this->lines * this->cols; i++)
        p[i] = pvalue[tail++];
}
void Matrix::set(int i, int j, double value)
{
    p[i * this->cols + j] = value;
}
double& Matrix::at(int i, int j)
{
    return p[i * this->cols + j];
}
double Matrix::at(int i, int j) const
{
    return p[i * this->cols + j];
}
int Matrix::get_lines() const
{
    return this->lines;
}
int Matrix::get_cols() const
{
    return this->cols;
}
void Matrix::print() const
{
    for (int i = 0; i < this->lines; i++)
    {
        for (int j = 0; j < this->cols; j++)
            std::cout << this->p[i * this->cols + j] << " ";
        std::cout << std::endl;
    }
}

#endif

task5.cpp

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

int main()
{
    using namespace std;

    double x[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};

    Matrix m1(3, 4);    // 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;
    for (int i = 0; i < 4; i++)
        cout << m1.at(0, i) << " ";
    cout << endl
         << endl;

    Matrix m2(4, 3);
    m2.set(x);
    m2.print();
    cout << "the first line is: " << endl;
    for (int i = 0; i < 3; i++)
        cout << m2.at(0, i) << " ";
    cout << endl
         << endl;
    
    Matrix m3(m2);
    m3.set(0, 0, 999);
    m3.print();
}

运行截图：