实验六

task3

task3_1.cpp:

#include <iostream>
#include <fstream>
#include <array>
#define N 5

int main() {
    using namespace std;

    array<int, N> x {97, 98, 99, 100, 101};

    ofstream out;
    out.open("data1.dat", ios::binary);
    if(!out.is_open()) {
        cout << "fail to open data1.dat\n";
        return 1;
    }

    out.write(reinterpret_cast<char *>(&x), sizeof(x));
    out.close();
}

 

task3_2.cpp:

#include <iostream>
#include <fstream>
#include <array>
#define N 5

int main() {
    using namespace std;
    array<char, N> x;

    ifstream in;
    in.open("data1.dat", ios::binary);
    if(!in.is_open()) {
        cout << "fail to open data1.dat\n";
        return 1;
    }

    in.read(reinterpret_cast<char *>(&x), sizeof(x));
    in.close();

    for(auto i = 0; i < N; ++i)
        cout << x[i] << ", ";
    cout << "\b\b \n";
}

 

task4

Vector.hpp:

#pragma once
using std::cout;
using std::endl;
template <typename T>
class Vector
{
private:
    int size;
    T* p;

public:
    Vector(int);
    Vector(int, T);
    Vector(const Vector<T>& x);
    ~Vector();
    int get_size() const;
    T& at(int x);
    T& operator[](int x);
    template <typename T1>
    friend void output(Vector<T1>& x);
};

template <typename T>
Vector<T>::Vector(int n) : size{ n }
{
    p = new T[n];
}

template <typename T>
Vector<T>::Vector(int n, T x) : size{ n }
{
    p = new T[n];
    for (int i = 0; i < n; i++)
    {
        p[i] = x;
    }
}

template <typename T1>
Vector<T1>::Vector(const Vector<T1>& x) : size{ x.size }
{
    p = new T1[size];
    for (auto i = 0; i < size; i++)
    {
        p[i] = x.p[i];
    }
}

template <typename T>
Vector<T>::~Vector()
{
    delete[] p;
}

template <typename T>
int Vector<T>::get_size()const {
    return size;
}

template <typename T>
T& Vector<T>::at(int x) {
    return p[x];
}

template<typename T>
T& Vector<T>::operator[](int x) {
    return p[x];
}

template<typename T1>
void output(Vector<T1>& x) {
    for (int i = 0; i < x.size; i++)
        cout << x.p[i] << " ";
    cout << endl;
}

task4.cpp:

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

void test() {
    using namespace std;

    int n;
    cin >> n;

    Vector<double> x1(n);
    for (auto i = 0; i < n; ++i)
        x1.at(i) = i * 0.7;

    output(x1);

    Vector<int> x2(n, 42);
    Vector<int> x3(x2);

    output(x2);
    output(x3);

    x2.at(0) = 77;
    output(x2);

    x3[0] = 999;
    output(x3);
}

int main() {
    test();
}

task5:

#include<iostream>
#include <fstream>
#include<iomanip>
using namespace std;
void output(ostream& out)
{
    char i,m;
    int p, k;
    out << "  ";
    for (i = 'a'; i <= 'z'; i++)
    {
        out << setw(2) << i;
    }
    out << endl;
    for (k = 1; k <= 26; k++)
    {
        out << setw(2) << k;
        for (p = k; p < k + 26; p++)
        {
            m = 'A' + p % 26;
        out << setw(2) << m;
        }
        out << endl;
    }
}
int main()
{
    output(cout);
    ofstream out;
    out.open("cipher_key.txt");
    if (!out.is_open()) {
        cout << "fail to open file cipher_key.txt to write" << endl;
        return 0;
    }
    output(out);
    out.close();
}