实验四

实验四

vectorInt.hpp

#pragma once

#include<iostream>

using namespace std;

class vectorInt {
public:
    vectorInt(int a);
    vectorInt(int a, int value);
    vectorInt(const vectorInt& vp);
    ~vectorInt();

    //其他成员函数
    int &at(int i);
    int get_size();
    //友元函数
    friend void output(vectorInt t);
private:
    int n;
    int* p;
};

vectorInt::vectorInt(int a) :n{ a } 
{
    p = new int[n]();     //分配动态内存
    cout << "constructor1 called" << endl;
}

vectorInt::vectorInt(int a, int value) :n{ a }
{
    p = new int[n];
    for (int i = 0; i < n; i++)
    {
        p[i] = value;
    }
    cout << "constructor2 called" << endl;
}

vectorInt::vectorInt(const vectorInt &vp):n{vp.n}
{
    p = new int[n];
    for (int i = 0; i < n; i++)
    {
        p[i] = vp.p[i];   //深复制
    }
    cout << "copy constructor called" << endl;
}
vectorInt::~vectorInt() { 
    delete[] p; 
    cout << "destructor called" << endl; 
}

int& vectorInt::at(int i) {
    return p[i];
}

int vectorInt::get_size() {
    return n;
}
void output(vectorInt t) {
    for (int i = 0; i < t.n; i++) 
        cout << t.p[i]<<",";
    cout << endl;
}

task_5.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();
}

截图

task_6

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();                         //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
};

// 类Matrix的实现：待补足
// ×××
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];
}

Matrix::~Matrix()
{
    delete[]p;
}

void Matrix::set(const double* pvalue)
{
    for (int i = 0; i < (lines * cols); i++)
    {
        p[i] = pvalue[i];
    }
}

void Matrix::set(int i, int j, int value)
{
    int n = i * cols + j;
    p[n] = value;
}

double& Matrix::at(int i, int j)
{
    int n = i * cols + j;
    return p[n];
}

double Matrix::at(int i, int j) const
{
    int n = i * cols + j;
    return p[n];
}

int Matrix::get_lines() const
{
    return lines;
}

int Matrix::get_cols() const
{
    return cols;
}

void Matrix::print() const
{
    for (int i = 0; i < (lines * cols); i++)
    {
        cout << p[i] << ",";
        if ((i+1) % cols == 0)
            cout << endl;
    }
    cout << endl;
}

task_6.cpp

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

void test() {
    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;  // 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, 999);  // 将矩阵m3第0行第0列元素值设为999
    m3.print();
}

int main() {
    test();
}

截图