实验四

• 实验任务5

代码：

vectorInt.hpp:

#pragma once
#include<iostream>
#include<cassert>
using namespace std;
class vectorInt {
    int size, * p;
public:
    vectorInt(int size0);
    vectorInt(int size0, int value);
    vectorInt(const vectorInt& obj);
    ~vectorInt();
    int& at(int i);
    int get_size() const{ return size; }
    friend void output(vectorInt &V);
};
int& vectorInt::at(int i)
{
    if(i >= 0 && i < size)
        return p[i];
}
vectorInt::vectorInt(int size0) {
    size = size0;
    cout << "constructor 1 called. " << endl;
    p = new int[size];
}
vectorInt::vectorInt(int size0, int value) {
    cout << "constructor 2 called. " << endl;
    size = size0;
    p = new int[size];
    for (int i = 0; i < size; i++)
        p[i] = value;
}
vectorInt::vectorInt(const vectorInt& obj) {
    cout << "copy constructor called. " << endl;
    size = obj.size;
    p = new int[size];
    for (int i = 0; i < size; i++)
        p[i] = obj.p[i];
}
vectorInt::~vectorInt() {
    cout << "destructor called. " << endl;
    delete[]p;
}
 void output(vectorInt &V)
{
     for (int i = 0; i < V.size; i++)
         cout << V.p[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();
}

运行截图：

 

• 实验任务六

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
};

// 类Matrix的实现：待补足
// ×××

Matrix::Matrix(int n) {
    lines = n, cols = n;
    p = new double[lines*cols];
}
Matrix::Matrix(int n, int m) {
    lines = n, cols = m;
    p = new double[lines * cols];
}
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) {
    int i;
        for (i = 0; i < lines*cols; i++)
        {
            p[i] = *pvalue;
            pvalue++;
        }
}
void Matrix::set(int i, int j,int value) {
    p[i * lines + j] = value;
}
double& Matrix::at(int i, int j) {
    return p[i * lines + j];
}
double Matrix::at(int i, int j)const {
    return p[i * lines + j];
}
int Matrix::get_lines()const {
    return lines;
}
int Matrix::get_cols()const {
    return cols;
}
void Matrix::print()const {
    int i, j;
    for (j = 1; j <= lines; j++)
    {
        for (i = 1; i <= cols; i++)
            cout << p[(j - 1) * cols + i - 1] << " ";
        cout << endl;
    }
}

 

task6.cpp:

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

void test() {
    using namespace std;

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

    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;  // 输出矩阵m1第1行两个元素的值
    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构造新的矩阵m3
    m3.set(1, 2, 555);  // 将矩阵m3第0行第0列元素值设为999
    m3.print();
}

int main() {
    test();
}

运行截图：