实验三 类与对象

vector_int hpp:

#include <iostream>
using namespace std;

class vector_int
{
public:
    vector_int(int n);
    vector_int(int n, int m);
    vector_int(const vector_int &obj);
    ~vector_int()
    {
        delete[] p;
        cout << "deleted" << endl;
    }
    int &at(int i);

private:
    int *p;
    int size;
};

vector_int::vector_int(int n)
{
    p = new int[n];
    size = n;
    cout << "已经申请" << n << "个int大小的空间" << endl;
}

vector_int::vector_int(int n, int m)
{
    p = new int[n];
    size = n;
    for (int i = 0; i < n; i++)
        p[i] = m;
    cout << "已经申请" << n << "个int大小的空间，且初始值为" << m << endl;
}

vector_int::vector_int(const vector_int &obj)
{
    p = new int[obj.size];
    size = obj.size;
    for (int i = 0; i < size; i++)
        p[i] = obj.p[i];
}

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

task4.cpp:

#include <iostream>
#include "vector_int.hpp"
using namespace std;

int main()
{
    int n, m;
    cin >> n >> m;
    vector_int x1(n);
    vector_int x2(n, m);
    vector_int y(x2);
    y.at(0) = 999;
    for (int i = 0; i < n; i++)
        cout << y.at(i) << " ";
    cout << endl;

    return 0;
}

matrix.hpp:

#ifndef MATRIX_H
#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
};

// 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];
    for (int i = 0; i < lines * cols; i++)
        p[i] = X.p[i];
}
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)
{
    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 (int i = 0; i < lines; i++)
    {
        for (int j = 0; j < cols; j++)
            cout << p[i * cols + j] << " ";
        cout << endl;
    }
}

#endif

task5.cpp:

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

int main()
{
    using namespace std;

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

    Matrix m1(4, 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, 4);
    m2.set(x);
    m2.print();
    cout << "the first line is: " << endl;
    cout << m2.at(0, 0) << " " << m2.at(0, 1) << " " << m2.at(0, 2) << " " << m2.at(0, 3) << endl;
    cout << endl;

    Matrix m3(m2);
    m3.set(0, 0, 999);
    m3.print();
}