实验四

task5

代码hpp

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

class vectorInt
{
private:
    int n, x;//n为数组长度，x为默认初始值
    int* p;//数组
public:
    vectorInt(int n0) :n(n0), x(0)
    {
        p = new int[n];
        for (int i = 0; i < n0; i++)
            p[i] = x;
        cout << "constructor1 called"<<endl;
    };//构造函数
    vectorInt(int n0, int x0) :n(n0), x(x0)
    {
        p = new int[n];
        for (int i = 0; i < n0; i++)
            p[i] = x;
        cout << "constructor2 called" << endl;
    };//构造函数
    vectorInt(const vectorInt& y)//复制构造函数
    {
        n = y.n;
        x = y.x;
        p = new int[n];
        for (int i = 0; i < n; i++)
            p[i] = y.p[i];
        cout << "copy consturctor called" << endl;
    }

    friend void output(const vectorInt& obj);
    ~vectorInt()//析构函数
    {
        delete[] p;
        cout << "destructor called" << endl;
    }

    int& at(int index);//返回下标为index的数据引用



};
 void output(const vectorInt& obj) {
     for (int i = 0; i < obj.n; i++) {
                 cout << obj.p[i]<< ", ";
     }
       cout << endl;
}


int& vectorInt::at(int index)
{
    assert(index >= 0 && index < n);
    return p[index];
}

测试代码

#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();
}

测试结果

task6

hpp

#pragma once#define MATRIX_H
#include <iostream>
#include <cassert>
using namespace std;
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[X.lines * X.cols];
    for (int i = 0; i < lines * cols; i++)
    p[i] = X.p[i];
}
Matrix::~Matrix()
{
    if (p != NULL)
    {
        delete []p;
        p = NULL;
    }
}
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)
{
    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 * lines + 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++)
        {
            cout << p[i * cols + j] << ", ";
        }
        cout << "\b\b " << endl;
    }
}

测试代码

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

void test() {
    using namespace std;

    double x[] = { 7, 2, 4, 9, 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, 621);  // 将矩阵m3第0行第0列元素值设为999
    m3.print();
}

int main() {
    test();
}

结果