实验四

实验4.5

#pragma once
#include<iostream>
using namespace std;
class vectorInt {
    friend void output(vectorInt&v);
public:
    vectorInt(int n);
    vectorInt(int n, int value);
    vectorInt(vectorInt& v);
    ~vectorInt() { cout << "destructor called \n"; delete[]vec; }
    
    int &at(int i);
    void get_size()const;
private:
    int size;
    int* vec;
};

//构造函数接口
vectorInt::vectorInt(int n){
    size = n;
    cout << "constructor called \n";
    vec = new int[size]();
}
//构造函数接口
vectorInt::vectorInt(int n, int value) {
    cout << "constructor called"<<endl;
    size = n;
    vec = new int[size];
    for (int i = 0; i < size; i++) {
        vec[i] = value;
    }
}
//复制构造函数接口
vectorInt::vectorInt(vectorInt& v) {
    cout << "copyconstructor called \n";
    size = v.size;
    vec = new int[size];
    for (int i = 0; i < size; i++)
        vec[i] = v.vec[i];
}

//获取数组大小
void vectorInt::get_size()const{
    cout << size<<endl;
}
//返回特定位置数组元素
int &vectorInt::at(int i){
    return vec[i];
}

//输出数组元素 函数接口
void output(vectorInt& v) {
    for (int i = 0; i < v.size; i++)
        cout << v.vec[i]<<" ";
    cout << endl;
}



#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();
}

实验4.6

#pragma once
#include <iostream>
using namespace std;
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;
};

//构造函数接口
Matrix::Matrix(int n) {
    lines = n, cols = n;
    p = new double[n * n];
}

//构造函数接口
Matrix::Matrix(int n, int m){
    lines = n, cols = m;
    p = new double[n * m];
}

//复制构造函数接口
Matrix::Matrix(const Matrix& X){
    lines = X.lines, cols = X.cols;
    p = new double[lines*cols];
    for (int i = 0; i < lines; i++)
        for (int j = 0; j < cols; j++)
            p[i*cols+j] = X.p[i*cols+j];
}
//析构函数接口
inline Matrix::~Matrix(){
    cout << "default constructor called\n";
    delete[]p;
}

//用pvalue指向的连续内存块数据按行为矩阵赋值
void Matrix::set(const double* pvalue){
    p = new double[lines * cols];
    for (int i = 0; i < lines; i++)
        for (int j = 0; j < cols; j++)
             p[i*cols+j] = *(pvalue++);
        
}

//设置矩阵第i行第j列元素值为value
void Matrix::set(int i, int j, int value){
    p[i*cols+j] = value;
}

//返回矩阵第i行第j列元素的引用
double& Matrix::at(int i, int j) {
    return p[i*cols+j];
}

//返回矩阵第i行第j列元素的值
double Matrix::at(int i, int j) const{
    return p[i*cols+j];
}

//返回矩阵行数
int Matrix::get_lines() const{
    return lines;
}

//返回矩列数
int Matrix::get_cols() const{
    return cols;
}

// 按行打印输出矩阵
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;
    }
}

#include <iostream>
#include "Matrix.hpp"
using namespace std;
void test() {
    double x[9] = {1,4,5};
    Matrix m1(3, 3); 
    m1.set(x); 
    m1.print(); 
    cout << "the first line is: " << endl;
    cout << m1.at(0, 0) << " " << m1.at(0, 1) <<" "<<m1.at(0, 2) << endl;
        cout << endl;
    Matrix m2(3, 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(1, 2, 999);
    m3.print();
}
int main() {
    test();
}