实验四

实验任务五

vectorint.hpp

#include<iostream>
using namespace std;
class vectorint {
public:
    vectorint(int n) {
        length = n;
        arr = new int[n];
        cout << "constructor 1 callled" << endl;
    }
    vectorint(int n, int m) {
        length = n;
        arr = new int[n];
        for (int i = 0; i < n; i++)arr[i] = m;
        cout << "constructor 2 callled" << endl;
    }
    vectorint(vectorint& x) {
        length = x.get_size();
        arr = new int[length];
        for (int i = 0; i < length; i++)arr[i] = x.arr[i];
        cout << "copy constructor called" << endl;
    }
    int& at(int n) {
        return arr[n];
    }
    int get_size() {
        return length;
    }
    ~vectorint() {
        cout << "destructor called" << endl;
    }


private:    
    int length;int *arr;
    friend void output(vectorint& x);
};
void output(vectorint& x) {
    for (int i = 0; i < x.get_size(); i++)
        cout << x.arr[i] << " ";
    cout << '\n';
}

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();
}

实验任务六

Matrix.hpp

#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
};

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];
}
void Matrix::set(const double* pvalue) {
    for (int i = 0; i < lines * cols; i++)
    {
        p[i] =* pvalue;
        pvalue++;
    }
}
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 * cols; i++)
    {
        cout << p[i] ;
        if (i > 0 && (i + 1) % cols == 0)cout << endl;
        else cout << ',';
    }
}
// 类Matrix的实现：待补足
// ×××

task6.cpp

#include <iostream>
#include "Matrix.hpp"
void test() {
    using namespace std;
    double x[] = { 1, 21, 13, 24, 45, 36 };
    Matrix m1(2, 3); // 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, 19); // 将矩阵m3第0行第0列元素值设为999
    m3.print();
}
int main() {
    test();
}

运行测试截图

更改数据后

总结

对于深复制和浅复制有了更多认识，但是一些前面的关键词类似于auto和一些语法用法有一些遗忘，调试也不够及时，课后还是要多加练习。