实验四

#include<iostream>
using namespace std;
class vectorInt {
    private:
        int n;
        int value;
        int* arr;
    public:
        vectorInt(int n0,int value0 = 0 )
        {   value = value0;
           n = n0;
            arr = new int[n]; 
            for (int i = 0; i < n; i++)
            {
                arr[i] = value;
            }
                cout << "constructor  called. "<<endl;
            
        };
        vectorInt(const vectorInt& v)
        {
            n = v.n;
            value = v.value;
            arr = new int[v.n];
            for (int i = 0; i < n; i++)
            {
                arr[i] = v.value;
            }
            cout << "copy constructor called." << endl;
        }
        ~vectorInt()
        {
            if (arr != NULL)
            {
                delete[]arr;
                arr = NULL;
            }
            cout << "destructer called." << endl;
        }
        
        int &at(int x)
        {
            return arr[x];
        }
        int output()
        {
            for (int i = 0; i < n; i++)
            {
                cout << arr[i] << " ";
            }
            cout << endl; return 0;
        }
        int get_size()
        {
            return n;
        }


};

void output(vectorInt & T) {
       for (int i = 0; i < T.get_size(); ++i) {
        cout << T.at(i) << ", ";
    }
    cout << "\b\b \n";
}

#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;
    x1.output();
    vectorInt x2(n, 42);
    vectorInt x3(x2);
    output(x2);
    output(x3);
    x2.at(0) = 77;
    output(x2);
    output(x3);
}
int main() {
    test();
}

#pragma once
#include<iostream>
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
    { delete[]p; }
    void set(const double* pvalue); // 用pvalue指向的连续内存块数据按行为矩阵
    
        void set(int i, int j, int value); //设置矩阵第i行第j列元素值为value
     //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)
{
         int k = 0;
       for (k = 0; k < lines * cols; k++) 
       {
             p[k] = pvalue[k];
        
       }
    
}

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

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



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) {
            if (j == cols - 1)
            {
                cout << p[i * cols + j] << endl;    
            }
                 else
            {
                cout << p[i * cols + j] << ", ";    
            }
        }
    }
}

#include <iostream>
#include "matrix.hpp"
void test() {
    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; // 输出矩阵m1第1行两个元素的值
        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); // 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();
}