实验四

实验任务5

vectorInt.hpp

#pragma once

#include<iostream>
#include<cassert>
using namespace std;

class vectorInt{
public:
    vectorInt(int s,int num=0);
    vectorInt(const vectorInt &x1);
    ~vectorInt();
    int &at(int i);
    friend void output(vectorInt &x1) ;
    
private:
    int size;
    int *p;
    static int count;
};

int vectorInt:: count =1;
vectorInt::vectorInt(int s,int num) { 
    size=s;
    p=new int[s];
    for(int i=0;i<size;i++){
        p[i]=num;
    }
    cout<<"constructor "<<count++<<" called"<<endl;
} 

vectorInt::vectorInt(const vectorInt &x1){
    size=x1.size;
    p=new int[x1.size];
    for(int i=0;i<size;i++){
        p[i]=x1.p[i];
    } 
    cout<<"copy constructor called"<<endl;
}

vectorInt::~vectorInt(){
    delete[] p;
    cout<<"destructor called"<<endl;
}

int & vectorInt::at(int i){
    assert(i>=0&&i<size);
    return p[i];
}

void output(vectorInt &x1) {
    for(auto i=0;i<x1.size;i++){
        cout<<x1.p[i]<<" ";
    }
    cout<<endl;
}

task.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();
}

运行结果

 

实验任务6

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
};

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){
    p[i*cols+j]=value;
}

double & Matrix::at(int i, int j){
    return p[i*cols+j];
}

double Matrix::at(int i, int j) const{
    return p[i*cols+j];
}

int Matrix::get_lines() 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<<p[i*cols+j]<<",";
        }
        cout<<"\b ";
        cout<<endl; 
    }
}

task.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(0, 0, 999);  // 将矩阵m3第0行第0列元素值设为999
    m3.print();
}

int main() {
    test();
}

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