2022.11.02 OOP实验课

实验4 类与数组、指针

任务5

代码：
vectorInt54.hpp

#pragma once

#include <iostream>
#include <cassert>
#include <iomanip>

using namespace std;

class vectorInt
{
private:
    int size;
    int *n;
public:
    vectorInt(int num);
    vectorInt(int num, int value);
    vectorInt(const vectorInt& obj);
    ~vectorInt();

    int &at( int i){ 
        assert( i >= 0 && i < size);//宏，通常测试用。如果步满足条件，终止程序
        return n[i];
    }
    int get_size(){ return size; }

    friend void output( vectorInt &x); 
};
 vectorInt:: vectorInt(int num): size{num}{
    n = new int[size];
    cout << "1 para constructor called." << endl;
}
 vectorInt:: vectorInt(int num, int value): size{num}{
    n = new int[size];
    for(int i = 0; i < num; ++i){
        n[i] = value;
    }
    cout << "2 para constructor called." << endl;
 }
 vectorInt::vectorInt(const vectorInt &obj): size{obj.size}{
    n = new int[size];
    for(int i = 0; i < size; ++i){
        n[i] = obj.n[i];
    }
    cout << "copy constructor called." << endl;
 }
 vectorInt::~vectorInt(){
    free(n);
    cout << "destructor called." << endl;
 }

 void output(vectorInt &x){
    for(int i = 0; i < x.size; ++i){
        cout << setw(3) << left << x.n[i];
    }
    cout << endl;
 }

task54.cpp

#include "vectorInt54.hpp"
#include <iostream>

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();
}

测试：

任务6

代码：
Matrix64.hpp

#pragma once

#include <iostream>
#include <iomanip>

using std::cout;
using std::endl;
using std::setw;
using std::left;

class Matrix{
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首地址

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列的值
    int get_line() const; //返回矩阵行数
    int get_cols() const; //返回矩阵列数
    void print() const; //按行打印输出矩阵
};

Matrix::Matrix(int n): lines{n}, cols{n}{
    p = new double*[n];
    for(int i = 0; i < n; i++){
        p[i] = new double[n];
    }
}
Matrix::Matrix(int n, int m): lines{n}, cols{m}{
    p = new double*[n];
    for(int i = 0; i < n; i++){
        p[i] = new double[m];
    }    
}
Matrix::Matrix(const Matrix &x): lines{x.lines}, cols{x.cols}{
    //初始化
    p = new double*[x.lines];
    for(int i = 0; i < x.lines; i++){
        p[i] = new double[x.cols];
    }
    //复制数值
    for(int i = 0; i < x.lines; i++){
        for(int j = 0; j < x.cols; j++){
            p[i][j] = x.p[i][j];
        }
    }
}
Matrix::~Matrix(){};

void Matrix::set(const double* pvalue){
    int k =0;
    for(int i = 0; i < lines; i++){
        for(int j = 0; j < cols; j++){
            p[i][j] = pvalue[k++];
        }
        
    }
}
void Matrix::set(int i, int j, int value){
    p[i][j] = value;
}
double& Matrix::at(int i, int j){
    return p[i][j];
}
double Matrix::at(int i, int j)const{
    return p[i][j];
}
int Matrix::get_line()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 << setw(3) << left << int(p[i][j]);
        }
        cout << endl;
    }
}

task64.cpp

#include "Matrix64.hpp"

#include <iostream>

void test(){
    using namespace std;

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

    Matrix m1(3, 2);//创建一个3x2的矩阵
    m1.set(x);//用一维数组x的值按行为m1赋值
    m1.print();//打印矩阵m1
    cout << "the first line is: " << endl;
    cout << m1.at(0, 0) << " " << m1.at(0, 1) << endl; //输出矩阵m1第1行的两个元素的值
    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);//用矩阵m2构造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();
}

测试：