实验六

#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";
}

 

 int占4个字节，char占1个字节

#pragma once
#include<iostream>
using namespace std;
template<typename T>
class Vector
{
public:
    Vector(T n):size(n)
    {
        p = new T[n];
    }
    Vector(T n, T value):size(n)
    {
        p = new T[n];
        for (int i = 0; i < size; i++)
        {
            p[i] = value;
        }
    }
    Vector(const Vector<T>& r):size(r.size)
    {
        p = new int[size];
        for (int i = 0; i < size; i++)
            p[i] = r.p[i];
    }
    ~Vector()
    {
        delete[] p;
    }
    T& at(int i)
    {
        return p[i];
    }
    T get_size()
    {
        return size;
    }
    friend void output(Vector<T>& x)
    {
        for (int i = 0; i < x.size; i++)
            cout << x.p[i] << " ";
        cout << endl;
    }
    T& operator[](int i)
    {
        return p[i];
    }
private:
    T size;
    T* p;
};

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

void test() {
    using namespace std;

    int n;
    cin >> n;

    Vector<double> x1(n);
    for (auto i = 0; i < n; ++i)
        x1.at(i) = i * 0.5;

    output(x1);

    Vector<int> x2(n, 66);
    Vector<int> x3(x2);

    output(x2);
    output(x3);

    x2.at(0) = 88;
    output(x2);

    x3[0] = 99;
    output(x3);
}

int main() {
    test();
}

 

 

#include<iostream>
#include<iomanip>
#include<fstream>
using namespace std;
void output(std::ostream& out)
{
   
    for (int i = 0; i < 27; i++)
    {
        if (!i)
        {
            out << "   ";         
            for (int j = 97; j < 123; j++)
            {
                out << char(j) << " ";              
            }
            out << endl;
            continue;
        }
        out << std::left << setw(2) << i << " ";      
        for (int j = i; j < i + 26; j++)
        {
            out << std::left << setw(2) << char(65 + j % 26);
        }
        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();
}