实验3 类和对象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 n0,int value0=0):n(n0),value(value0){
            cout << "constructor called." << endl;
            p=new int[n0];
            for(auto i=0; i<n; ++i)
                p[i] = value0;
        }
        Vector_int(const Vector_int &x);
        ~Vector_int();
        int &at(int i);
    private:
        int n;
        int value;
        int *p;
            
}; 
Vector_int::Vector_int(const Vector_int &x):n(x.n){
    p=new int[n];
    for(auto i=0; i<n; ++i)
        p[i] = x.p[i];
}
Vector_int::~Vector_int(){
    cout << "Destructor called." << endl;
    delete[] p;
}
int &Vector_int::at(int i){
    if(i>=0&&i<n)
      return p[i];
}
#endif

task4.cpp

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

using namespace std;
int main(){
    int n;
    cin>>n;
    Vector_int y(n,8);
    cout<<y.at(0)<<endl;
    cout<<y.at(1)<<endl;
    Vector_int x1(n);
    
    x1.at(0)=22;
    cout<<x1.at(0)<<endl;
    
    Vector_int x2(x1);
    x1.at(0)=11; 
    
    cout<<x1.at(0)<<endl;
    cout<<x2.at(0)<<endl;
    return 0;
    
}

 实验任务5

matrix.hpp

#ifndef MATRIX_H
#define MATRIX_H

#include <iostream>
#include <cassert>
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
    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;             //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(auto i=0;i<lines*cols;i++)
         p[i]=X.p[i]; 
}
Matrix::~Matrix(){
    delete[] p;
} 
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[lines*i+j]=value;
}
double &Matrix::at(int i,int j){
    return p[lines*i+j];
} 
double Matrix::at(int i,int j)const{
    return p[lines*i+j];
}
int Matrix::get_lines()const{
    return lines;
}
int Matrix::get_cols()const{
    return cols;
}
void Matrix::print()const{
    int k=0;
    for(auto i=0;i<lines;i++){
        for(auto j=0;j<cols;j++){
             if(j<cols-1)cout<<p[k++]<<",";
             else
               cout<<p[k++];
         }
         cout<<endl;
    }          
}
#endif

task.cpp

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

int main()
{
    using namespace std;

    double x[] = {6.6, 5, 7, 12, 9, 3.3};

    Matrix m1(3, 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;
    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, 0,25);
    m3.print();
}