实验4 类与数组、指针

task5 VectorInt.h

#pragma once

#include<iostream>
#include<cassert>

using namespace std;

class VectorInt {
public:
    VectorInt(int n);
    VectorInt(int n, int value);
    VectorInt(const VectorInt& vp);
    ~VectorInt();

public:
    int& at(int index);
    int get_size(int p[]) { return sizeof(p); }
    friend void output(VectorInt& x);
private:
    int size;
    int* p;
private:
    static int number;
};

int VectorInt::number = 0;

VectorInt::VectorInt(int n) :size{ n } {
    number++;
    cout << "constructor "<<number<<" called." << endl;
    p = new int[n];
}

VectorInt::VectorInt(int n, int value) :size{ n } {
    p = new int[n];
    for (auto i = 0; i < n; i++) {
        p[i] = value;
    }
} 

VectorInt::VectorInt(const VectorInt& vp) :size { vp.size } {
        number++;
    cout << "constructor "<<number<<" called." << endl;
    cout << "copy constuctor called" << endl;
    p = new int[size];
    for (auto i = 0; i < size; ++i) {
        p[i] = vp.p[i];
    }
}

VectorInt::~VectorInt() {
    cout << "destructor called" << endl;
}

int& VectorInt::at(int index) {
    return p[index];
}

void output(VectorInt& x) {
    for (auto i=0;i<x.size;i++)
        cout << x.p[i] << ", ";
    cout << "\b\b \n";
}

task5.cpp

#include <iostream>
#include "vectorInt.h"

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();
}

实验结果：

task6 Matrix.h

#pragma once

#include <iostream>

using std::cout;
using std::endl;

class Matrix {
public:
    Matrix(int n);
    Matrix(int n, int m);
    Matrix(const Matrix& X);
    ~Matrix();

    void set(const double* pvalue);
    void set(int i, int j, int value);
    double& at(int i, int j);
    double at(int i, int j) const;
    int get_lines() const;
    int get_cols() const;
    void print() const;

private:
    int lines;
    int cols;
    double* p;
};

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;
}

int Matrix::get_lines()const
{
    return lines;
}

int Matrix::get_cols() const
{
    return cols;
}

void Matrix::set(const double* pvalue)
{
    for (auto 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];
}

void Matrix::print() const {
    for (auto i = 0; i < lines; i++) {
        for (auto j = 0; j < cols; j++)
            cout << p[i * cols + j] << ", ";
        cout << "\b\b \n";
    }
}

task6.h

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

void test() {
    using namespace std;

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

    Matrix m1(3, 2);
    m1.set(x);
    m1.print();
    cout << "the first line is: " << endl;
    cout << m1.at(0, 0) << " " << m1.at(0, 1) << 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, 0, 999);
    m3.print();
}

int main() {
    test();
}

实验结果：