实验3 类和对象Ⅱ

task4：

vector_int.hpp源码：

 

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

class Vector_int {
public:
    Vector_int(int _size) :size(_size)
    {
        cout << "new vector is created." << endl;
        p = new int[_size];
        for ( int i = 0;i < size;i++ ) {
            p[i] = 0;
        }
    }
    Vector_int(int _size, int _x) :size(_size)
    {
        cout << "new vector is created, and the value is " << _x << endl;
        p = new int[_size];
        for ( int i = 0;i < size; i++ ) {
            p[i] = _x;
        }
    }
    Vector_int(const Vector_int& _vector) : size(_vector.size)
    {
        cout << "copy constructor....." << endl;
        p = new int[size];
        for ( int i = 0;i < size; i++ ) {
            p[i] = _vector.p[i];
        }
    }
    int& at(int _i)
    {
        assert(_i >= 0 && _i < size);
        return p[_i];
    }
    ~Vector_int()
    {
        cout << "delete........." << endl;
        delete[] p;
    }
private:
    int  size;
    int* p;
};

 

task4.cpp源码：

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

using namespace std;

int main()
{
    int n;
    cin >> n;
    Vector_int x1(n);
    cout << "Array_x1: ";
    for ( int i = 0;i < n;i++ ) {
        cout << x1.at(i) << " ";
    }//输出x1
    cout << endl;
    
    Vector_int x2(n, 6);
    cout << "Array_x2: ";
    for ( int i = 0;i < n;i++ ) {
        cout << x2.at(i) << " ";
    }//输出x2
    cout << endl;
    
    Vector_int y(x2);
    y.at(0) = 999;
    cout << "Array_y: ";
    for ( int i = 0;i < n;i++ ) {
        cout << y.at(i) << " ";
    }//输出y
    cout << endl;
    return 0;
}

运行结果：

 

 

.......................................................................

task5:

Matrix.hpp源码：

#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 * 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)
{
    assert(i >= 0 && i < lines&& j >= 0 && j < cols);
    p[i * cols + j] = value;
}
double& Matrix::at(int i, int j)
{
    assert(i >= 0 && i < lines&& j >= 0 && j < cols);
    return p[i * cols + j];
}
double Matrix::at(int i, int j) const
{
    assert(i >= 0 && i < lines&& j >= 0 && j < cols);
    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++ ) {
            std::cout << p[i * cols + j];
            if ( j != cols - 1 ) {
                std::cout << ", ";
            }
        }
        std::cout << std::endl;
    }
}
#endif

task5.cpp源码：

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

int main()
{
    using namespace std;

    double x[] = {1, 2, 30, 40, 5, 6};

    Matrix m1(2, 3);    // 创建一个2×3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) << " " << m1.at(0, 2) << 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, 1, 999);
    m3.print();
}

运行结果：

 

 总结：

深入理解了深复制与浅复制的区别

掌握了对cassert标准库的应用