实验四 类与数组、指针

实验任务五代码截图：

   vectorInt.hpp:

#pragma once

#include<iostream>
#include<cassert>
using namespace std;

class vectorInt
{
public:
    vectorInt(int n);
    vectorInt(int n, int value);
    vectorInt(const vectorInt& v);
    ~vectorInt();
    int& at(int index) const;
    int get_size() const;
    friend void output(const vectorInt& v);

private:
    int* p;
    int size;
};

vectorInt::vectorInt(int n) :size{ n }
{
    p = new int[size];
    cout << "constructor 1 called." << endl;
}
vectorInt::vectorInt(int n, int value) : size{ n }
{
    p = new int[size];
    for (auto i = 0; i < size; i++)
        p[i] = value;
    cout << "constructor 2 called." << endl;
}
vectorInt::vectorInt(const vectorInt& v)
{
    size = v.size;
    p = new int[size];
    for (auto i = 0; i < size; i++)
        p[i] = v.p[i];
    cout << "copy constructor called." << endl;
}
vectorInt::~vectorInt()
{
    free(p);
    cout << "destructor called." << endl;
}
int& vectorInt::at(int index) const
{
    return p[index];
}
int vectorInt::get_size() const
{
    return size;
}
void output(const vectorInt& v)
{
    for (auto i = 0; i < v.size; i++)
        cout << v.p[i] << ",";
    cout << "\b " << endl;
}

   task5.cpp:

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

void test()
{
    using namespace std;

    int n;
    cin >> n;

    vectorInt x1(n);
    for (auto i = 0; i < n; i++)
        x1.at(i) = i * i;
    output(x1);
    vectorInt x2(n, 42);
    vectorInt x3(x2);
    output(x2);
    output(x3);
    x2.at(0) = 77;
    output(x2);
    output(x3);
}
int main()
{
    test();
}

运行截图：

 

 实验任务六代码：

 Matrix.hpp:

#pragma once
#include <iostream>
using std::cout;
using std::endl;
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() = default; //析构函数
    void set(const double* pvalue); // 用pvalue指向的连续内存块数据按行为矩阵赋值
    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)
{
    p = new double[n * n];
    lines = n;
    cols = n;
}
Matrix::Matrix(int n, int m)
{
    p = new double[n * m];
    lines = n;
    cols = m;
}
Matrix::Matrix(const Matrix& X)
{
    lines = X.lines;
    cols = X.cols;
    p = new double[lines * cols];
    for (auto i = 0; i < lines * cols; i++)
            p[i] = X.p[i];
}
void Matrix::set(const double* pvalue)
{
    for (auto i = 0; i < lines * cols; i++)
        p[i] = pvalue[i];
}
void Matrix::set(int i, int j, int value)
{
    p[i * cols + j] = value;
}
double& Matrix::at(int i, int j)
{
    return p[i * cols + j];
}
double Matrix::at(int i, int j) const
{
    return p[i * cols + j];
}
int Matrix::get_lines() const
{
    return lines;
}
int Matrix::get_cols() const
{
    return cols;
}
void Matrix::print() const
{
    for (auto i = 0; i < lines; i++)
    {
        for (auto j = 0; j < cols; j++)
            cout << p[i * cols + j] << ",";
        cout << "\b " << endl;
    }
}

 task6.cpp:

#include <iostream>
#include "matrix.hpp"
void test() {
    using namespace std;
    double x[] = { 2, 4, 6, 8, 10, 12 };
    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; // 输出矩阵m1第1行两个元素的值
        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); // 用矩阵m2构造新的矩阵m3
    m3.set(0, 0, 666); // 将矩阵m3第0行第0列元素值设为666
    m3.print();
}
int main() {
    test();
}

代码运行截图：