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";
}

vector.hpp

#pragma once
#include<iostream>
using namespace std;
template<typename T>
class Vector{
    public:
        Vector(int n):size{n}{
        value=new T[n];        
        }
        
        Vector(int n,T v):size{n}{
        value=new T[n];
        
        for(int i=0;i<n;i++)
        value[i]=v;
        }
        
        Vector(const Vector<T> &a):size{a.size}{
            value=new T[size];
            for(int i=0;i<size;i++)
            value[i]=a.value[i];
        }
        
        T &operator[](int i){
            return value[i];
        }
        
        int get_size() const{
        return size;
        }

        T &at(int index){
            return value[index];
        }
        
        friend void output(const Vector<T> &a){
        for(int i=0;i<a.size;i++)
        cout<<a.value[i]<<",";
        cout<<"\b\b\n";
        }
        
    private:
        int size;
        T *value;
};

task4

#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*0.3;
    
    output(x1);
    
    Vector<int> x2(n,33);
    Vector<int> x3(x2);
    
    output(x2);
    output(x3);
    
    x2.at(0)=22;
    output(x2);
    
    x3[0]=222;
    output(x3);
}
int main(){
    test();
}

task5

#include<iostream>
#include<string>
#include<iomanip>
#include<fstream>
using namespace std;

string stand = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
void output(std::ostream& out)
{
    int row = 1;
    out << "   ";
    for (int i = 0; i < 26; i++)
        out << (char)(stand[i] + 32) << " ";
    out << endl;
    while (row <= 26)
    {
        out << setw(2) << row << " ";
        for (int i = 0; i < 26; i++)
            out << stand[(i + row) % 26] << " ";
        out << endl;
        row++;
    }
}
int main()
{
    ofstream out;
    out.open("ciper.txt");
    if (!out.is_open())
    {
        std::cout << "fail to open ciper.txt" << endl;
        return 1;
    }
    output(out);
    output(std::cout);
    return 0;
}