实验四

vectorInt.hpp

#pragma once

#include <cassert>
#include <iostream>

using namespace std;

class vectorInt{
public:
    vectorInt(int n);
    vectorInt(int n, int value);
    vectorInt(const vectorInt &vi); 
    ~vectorInt();
    
    int &at(int index);
    int get_size() const;
    friend void output(vectorInt &x);
    
private:
    int size;
    int *p;
};

vectorInt::vectorInt(int n) : size{n} {
    cout << "dynamic create array..." << endl;
    p = new int[n];
}

vectorInt::vectorInt(int n, int value): size{n} {
    cout << "dynamic create array..." << endl;
    
    p = new int[n];
    for(int i=0;i<size;i++)
        p[i]=value;
}

vectorInt::vectorInt(const vectorInt &vi): size{ vi.size } {
    cout << "copy array..." << endl;
    p = new int[size];
    
    for(auto i = 0; i < size; ++i)
        p[i] = vi.p[i];
}

vectorInt::~vectorInt() {
    cout << "dynamic delete array..." << endl;
    delete[] p;
}

int &vectorInt::at(int index) {
    assert(index >= 0 && index < size);
    return p[index];
}

void output(vectorInt &x)
{
    for(auto i=0;i<=x.size-1;++i)
    {
        cout << x.at(i) << " " ; 
    }
    cout << endl;
}

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();
}

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[X.lines*X.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){
    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;i++) {
            for(int j=0;j<cols;j++) {
                cout << p[i*cols+j] << ", ";
            }
            cout << endl;
        } 
}

task6.cpp

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

void test() {
    using namespace std;

    double x[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
    
    Matrix m1(4, 3);    // 创建一个4*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;  // 输出矩阵m1第1行三个元素的值
    cout << endl;

    Matrix m2(3, 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();
}