实验六

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<int, 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";
}

修改后

#include<iostream>
#include<fstream>
#include<array>
#define N 5
int main(){
    using namespace std;
    array<char,N>x;
    ifstream in;
    in.open("data.txt",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";
}

Vector.hpp
#pragma once
#include<iostream>
#include<cassert>

using namespace std;

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

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

    Vector(const Vector& v) :size{ v.size } {
        p = new T[size];
        for (int i = 0; i < size; i++) {
            p[i] = v.p[i];
        }
    }

    ~Vector() {
        delete[] p;
    }

    int get_size() { 
        return size; 
    }

    T& at(int index) {
        assert(index >= 0 && index < size);
        return p[index];
    }

    T& operator[](int index) {
        assert(index >= 0 && index < size);
        return p[index];
    }

    template<typename T1>
    friend void output(const Vector<T1>& v);
private:
    int size;
    T* p;
};

template<typename T1>
void output(const Vector<T1>& v) {
    for (int i = 0; i < v.size; i++) {
        cout << v.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.cpp
#include<iostream>
#include <fstream>
#include<string>
#include<iomanip>
using namespace std;
void output(std::ostream& out)
{
    string a[27][27] = { " " };
    int n = 0;
    for (int i = 1; i < 27; i++)
    {
        a[i][0] = to_string(i);
        a[0][i] = 97 + n;
        n++;
    }
    for (int i = 1; i < 27; i++)
    {
        n = i;
        for (int j = 1; j < 27; j++)
        {
            if (65 + n > 90)
            {
                a[i][j] = 65 + n - 26;
            }
            else
            {
                a[i][j] = 65 + n;
            }
            n++;
        }
    }
    for (int i = 0; i < 27; i++) {
        for (int j = 0; j < 27; j++) {
            out <<right<< setw(2) << a[i][j] << " ";
        }
        out << endl;
    }
}
 
int main()
{
    ofstream out;
    out.open("cipher_key.txt", ios::out);
        if (!out.is_open())
        {
            cout << "fail to open file\n";
            return 1;
        }
        output(out);
        output(cout);
        out.close();
}