实验六

实验三

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;
    }
    // 把从地址&x开始连续sizeof(x)个字节的数据块以字节数据块方式写入文件data1.txt
    out.write(reinterpret_cast<char*>(&x), sizeof(x));
    out.close();
}

结果：

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;
    }
    // 从文件流对象in关联的文件data1.dat中读取sizeof(x)字节数据写入&x开始的地址单元
    in.read(reinterpret_cast<char*>(&x), sizeof(x));
    in.close();
    for (auto i = 0; i < N; ++i)
        cout << x[i] << ", ";
    cout << "\b\b \n";
}

结果：

修改后

结果：

原因：

录入记事本中的数据中，ab之间有三个空格字符，使用int类型时会将其空格字符自动忽略，而char类型会将空格字符一同录入。

实验四

Vector.hpp

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

task.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();
}

结果

 

修改数据后

#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, 16);
    Vector<int> x3(x2);
    output(x2);
    output(x3);
    x2.at(0) = 66;
    output(x2);
    x3[0] = 99;
    output(x3);
}
int main() {
    test();
}

结果

实验五

task_5.cpp

#include <iostream>
#include<fstream>
#include<string>
using namespace std;
void output(std::ostream& out) {
    string a[27][27];
    int i, j, n = 0;
    for (i = 1; i < 27; i++) {
        a[i][0] = to_string(i);
        a[0][i] = 97 + n;
        n++;
    }
    for (i = 1; i < 27; i++) {
        n = i;
        for (j = 1; j < 27; j++) {
            if (65 + n > 90)
            {
                a[i][j] = 65 + n - 26;
            }
            else {
                a[i][j] = 65 + n;
            }
            n++;
        }
    }
    for (i = 0; i < 27; i++) {

        for (j = 0; j < 27; j++) {
            cout << a[i][j] << " ";
            out << a[i][j] << " ";
        }
        cout << endl;
        out << endl;
    }
}
int main() 
{
    ofstream out;
    out.open("cipher_ke.txt");
    if (!out.is_open()) {
        cout << "fail to open cipher_key.txt to write" << endl;
    }
    output(out);
    out.close();
}

结果：