实验三

task4.hpp

#include <iostream>
using std::cout;
using std::endl;
class Vector_int
{
public:
    Vector_int(int n);
    Vector_int(int n,int m);
    ~Vector_int();
    Vector_int(Vector_int& X);
    void print();
    int& at(int i);
private:
    int size;
    int* p;
};
Vector_int::Vector_int(int n)
{
    p = new int[n];
    size = n;
    cout << "constructor called." << endl;
}
Vector_int::Vector_int(int n, int m)
{
    p = new int[n];
    for (int i = 0; i < n; i++)
        p[i] = m;
    size = n;
    cout << "constructor called." << endl;
}
Vector_int::~Vector_int()
{
    delete[] p;
    cout << "Destructor called." << endl;
}
Vector_int::Vector_int(Vector_int& X)
{
    size = X.size;
    p = new int[X.size];
    for (auto i = 0; i < size; ++i)
        p[i] = X.p[i];
}
int& Vector_int::at(int i)
{
    return p[i];
}
void Vector_int::print()
{
    for (auto i = 0; i < size; ++i)
        cout << p[i]<<" ";
    cout << endl;
}

task4.cpp

#include<iostream>
#include"Vector.hpp"
int main()
{
    Vector_int x(4,9); 
    Vector_int y(x);
    y.print();
    y.at(0) = 999;
    y.print();
}

运行截图：

 

task5.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, int 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
};
Matrix::Matrix(int n)
{
    lines = n; cols = n;
    p = new double[n * n];
}
Matrix::Matrix(int n, int m)
{
    lines = n; cols = m;
    p = new double[n * m];
}
Matrix::Matrix(const Matrix& X)
{
    lines = X.lines; cols = X.cols;
    p = new double[lines*cols];
    for (int i = 0; i < lines; i++)
        for (int j = 0; j < cols; j++)
            p[cols * i + j]=X.p[cols * i + j];
}
Matrix::~Matrix()
{
    delete[] p;
}
void Matrix::set(const double* pvalue)
{
    for (int i = 0; i < lines; i++)
        for (int j = 0; j < cols; j++)
            p[cols * i + j] = *pvalue++;
}
void Matrix::set(int i, int j, int value)
{
    p[cols * i + j] = value;
}
double& Matrix::at(int i, int j)
{
    return p[cols * i + j];
}
double Matrix::at(int i, int j) const
{
    return p[cols * i + j];
}
int Matrix::get_lines() const
{
    return lines;
}
int Matrix::get_cols() const
{
    return cols;
}
void Matrix::print() const
{
    for (int i = 0; i < lines; i++)
    {
        for (int j = 0; j < cols; j++)
            std::cout<<p[cols * i + 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 };

    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, 0, 999);
    m3.print();
}

运行截图：