实验三 类与对象Ⅱ

实验任务4

vector_int.hpp

#ifndef VECTOR_INT_HPP
#define VECTOR_INT_HPP
#include<iostream>
using namespace std;
class vector_int {
public:
    vector_int(int n, int value=0) {
        num = n;
        q = new int[num];
        for (int i = 0; i < num; i++)
            q[i] = value;
        cout << "constructing..."<<endl;
    };
    vector_int(vector_int& v) {
        num = v.num;
        q = new int[num];
        for (int i = 0; i < num; i++)
            q[i] = v.at(i);
        cout << "copy constructing..."<<endl;
    };
    int& at(int i) {
        if (i >= 0 && i < num)
            return q[i];
        else
            cout << "out of range";
    };
    ~vector_int() {
        delete[] q;
        cout << "deleting..."<<endl;
    };
    void print() {
        for (int i = 0; i < num; i++) 
            cout << q[i] << " ";
        cout << endl;
    };
private:
    int *q;
    int num;
};
#endif

task4.cpp

#include"vector_int.hpp"
#include<iostream>
int main() {
    int n;
    std::cout << "输入数组大小：";
    std::cin >> n;
    vector_int x(n);
    x.print();
    vector_int z(n, 6);
    z.print();
    vector_int y(z);
    y.print();
    y.at(0) = 999;
    y.print();
}

运行结果截图

 实验任务5

matrix.hpp

#ifndef MATRIX_H
#define MATRIX_H

#include <iostream>
#include <cassert>

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 {
        return lines;
    };                                  //返回矩阵行数
    int get_cols() const {
        return cols;
    };                                  //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];
}
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) {
    int n = cols * i + j ;
    p[n] = value;
}
double& Matrix::at(int i, int j) {
    int n = cols * i + j ;
    return p[n];
}
double Matrix::at(int i, int j) const {
    int n = cols * i + j ;
    return p[n];
}
void Matrix::print() const{
    int n = 0;
    for (int i = 0; i < lines; i++)
    {
        for (int j = 0; j < cols; j++)
            std::cout << p[n++] << ", ";
        std::cout << "\b\b \n";
    }
}
#endif

task5.cpp

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

int main()
{
    using namespace std;

    double x[] = { 0,9,8,7,6,5,4,3,2,1,2,3 };

    Matrix m1(3, 4);    // 创建一个3*4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) << " " << m1.at(0, 3) << endl;
    cout << endl;

    Matrix m2(4, 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(3, 2, 555);
    m3.print();
}

运行结果截图