实验四

vectorInt.hpp

#pragma once
#include<iostream>
using namespace std;
class vectorInt
{
private:
    int size;
    int* p;
public:
    vectorInt(int n) :size{ n } { 
        cout << "constructor1 called." << endl;
        p = new int[size]; 
    }
    vectorInt(int n, int value):size { n } {
        cout << "constructor2 called." << endl;
        p = new int[size];
        for (auto i = 0; i < size; i++)
            p[i] = value;
        cout << "one" << endl;
    }
    vectorInt(const vectorInt& obj):size {obj.size} {
        cout << "copy constructor called." << endl;
        p = new int[size];
        for (auto i = 0; i < size; i++)
            p[i] = obj.p[i];
    }
    ~vectorInt() {
        cout << "dynamic delete array..." << endl;
        delete[] p;
    }

    int& at(int index)
    {
        if (index >= 0 && index < size)
            return p[index];
    }
    int get_size()const
    {
        return size;
    }

    friend void output(vectorInt& obj1)
    {
        int i;
        for (i = 0; i < obj1.size; i++)
            cout << obj1.p[i] << " ";
        cout << endl;
    }
};

task 5

#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();
}

Matrix.hpp

#pragma once
#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
	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];
}
Matrix::Matrix(int n, int m) : lines{ n }, cols{ m } {
	p = new double[n * m];
}
Matrix::Matrix(const Matrix& obj) : lines{ obj.lines }, cols{ obj.cols } {
	p = new double[lines * cols];
	for (auto i = 0; i < lines; i++)
		for (auto j = 0; j < cols; j++)
			p[i * cols + j] = obj.p[i * cols + j];
}
Matrix::~Matrix() {
	delete []p;
}

void Matrix::set(const double* pvalue)
{
	for (auto i = 0; i < lines; i++)
	{
		for (auto j = 0; j < cols; j++)
		{
			p[i * cols + j] = *pvalue;
			pvalue++;
		}
	}
}
void Matrix::set(int i, int j, int value) {
	if (i >= 0 && i < lines && j >= 0 && j < cols) {
		p[i * cols + j] = value;
	}
}
double& Matrix::at(int i, int j) {
	if (i >= 0 && i < lines && j >= 0 && j < cols) {
		return p[i * cols + j];
	}
}
double Matrix::at(int i, int j) const {
	if (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 (auto i = 0; i < lines; i++) {
		for (auto j = 0; j < cols; j++)
			cout << p[i * cols + j] << " ";
		cout << endl;
	}
}

task 6

#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4×2的矩阵
	m1.set(x); // 用一维数组x的值按行为矩阵m1赋值
	m1.print(); 
	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) << 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();
}

数据修改后为：