实验3 数组、指针与现代c++标准库

1.实验任务1

程序源码

task1_1

#include <iostream>

using std::cout;
using std::endl;

class A{
public:
    A(int x0, int y0): x{ x0 }, y{ y0 } {}
    void show() const { cout << x << ", " << y << endl; }
private:
    int x, y;
};

class B{
public:
    B(double x0, double y0): x{ x0 }, y{ y0 } {}
    void show() const { cout << x << ", " << y << endl;}
private:
    double x, y;
};

int main() {
    A a(3, 4);
    a.show();

    B b(3.2, 5.6);
    b.show();
}

测试截图

task1_2

#include <iostream>
#include <string>

using std::cout;
using std::endl;

template<typename T>
class X{
public:
    X(T x0, T y0): x{x0}, y{y0} {}
    void show() const { cout << x << ", " << y << endl;}
private:
    T x, y;
};

int main() {
    X<int> x1(3, 4);
    x1.show();

    X<double> x2(3.2, 5.6);
    x2.show();

    X<std::string> x3("hello", "c plus plus");
    x3.show();
}

测试截图

2.实验任务2

程序源码

task2_1

#include <iostream>
#include <string>

int main() {
    using namespace std;

    string s1, s2;
    s1 = "nuist";                                 
    s1[0] = 'N';                                  
    s1.at(1) = 'U';                               
    cout << boolalpha << (s1 == "nuist") << endl; 
    cout << s1.length() << endl;                  
    cout << s1.size() << endl;                    
    s2 = s1 + ", 2050";                           
    cout << s2 << endl;

    string email{"xyz@gmail.com"};
    auto pos = email.find("@"); 
    if (pos == string::npos)
        cout << "illegal email address";
    else {
        auto s1 = email.substr(0, pos);  
        auto s2 = email.substr(pos + 1); 
        cout << s1 << endl;
        cout << s2 << endl;
    }

    string phone{"15216982937"};
    cout << phone.replace(3, 5, string(5, '*')) << endl; 

    string s3{"cosmos"}, s4{"galaxy"};
    cout << "s3: " + s3 + " s4: " + s4 << endl;
    s3.swap(s4);
    cout << "s3: " + s3 + " s4: " + s4 << endl;

    string s5{"abc"};
    const char *pstr = s5.c_str(); 
    cout << pstr << endl;

    string s6{"12306"};
    int x1 = stoi(s6); 
    cout << x1 << endl;

    int x2 = 12306;
    string s7 = to_string(x2); 
    cout << s7 << endl;

    double x3 = 123.06;
    string s8 = to_string(x3); 
    cout << s8 << endl;
}

测试截图

程序源码

task2_2

#include <iostream>
#include <string>
#include <limits>

int main() {
    using namespace std;

    const int n = 10;
    string prompt = string(n, '*') + "Enter a string: " + string(n, '*') + '\n';
  
    cout << prompt;
    string s1;
    cin >> s1;  // 从输入流中提取字符串给s1,碰到空格、回车、Tab键即结束
    cout << "s1: " << s1 << endl;
    cin.ignore(numeric_limits<streamsize>::max(), '\n');  // 清空输入缓冲区

    cout << prompt;
    getline(cin, s1);  // 从输入流中提取一行字符串给s1,直到换行
    cout << "s1: " << s1 << endl;

    string s2, s3;
    cout << prompt;
    getline(cin, s2, ' ');  // 从输入流中提取字符串给s2,直到指定分隔符空格
    getline(cin, s3);
    cout << "s2: " << s2 << endl;
    cout << "s3: " << s3 << endl;
}

测试截图

程序源码

task2_3

#include <iostream>
#include <string>

int main() {
    using namespace std;

    string s;

    cout << "Enter words: \n";
    
    while( getline(cin, s) ) {
        for(auto &ch: s)
            ch = toupper(ch);
        cout << s << "\n";
    }
}

测试截图

程序源码

task2_4

#include <iostream>
#include <string>
#include <algorithm>

int main() {
    using namespace std;

    string s1;

    cout << "Enter words: \n";
    getline(cin, s1);
    cout << "original words: \n";
    cout << s1 <<endl;
    cout << "to uppercase: \n";
    transform(s1.begin(), s1.end(), s1.begin(), ::toupper);
    cout << s1 << endl;
}

测试截图

3.实验任务3

程序源码

task3_1

#include <iostream>
#include <vector>


template<typename T>
void output(const T &obj) {
    for(auto &item: obj)
        std::cout << item << ", ";
    std::cout << "\b\b \n";
}

int main() {
    using namespace std;

    vector<int> v1;                // 创建一个vector对象v1, 未指定大小, 元素是int型, 未初始化
    vector<int> v2(5);             // 创建一个vector对象v2, 包含5个元素,元素是int型,初始值是默认值0
    vector<int> v3(5, 42);         // 创建一个vector对象v3, 包含5个元素,元素是int型,指定初始值是42
    vector<int> v4{1, 9, 8, 4}; // 创建一个vector对象v4, 元素是int型,使用初始化列表方式
    vector<int> v5{v4};            // 创建一个vector对象v5, 使用已经存在的对象v4创建

    output(v2);
    output(v3);
    output(v4);
    output(v5);
}

测试截图

程序源码

task3_2

#include <iostream>
#include <vector>

using std::cout;
using std::endl;
using std::vector;

void output(const vector<int> &v) {
    cout << "v.size() = " << v.size() << endl;
    cout << "v.capacity() = " << v.capacity() << endl;
    cout << endl;
}

int main() {
    vector<int> v{42};
    output(v);

    v.push_back(55);
    v.push_back(90);
    output(v);

    for(auto i = 0; i < 8; ++i)
        v.push_back(i);
    output(v);

    v.pop_back();
    output(v);
}

测试截图

4.实验任务4

程序源码

task4

#include <iostream>
#include <vector>
#include <array>
#include <string>
#include <algorithm>

using namespace std;

// 函数模板
// 通过索引方式输出对象值
template<typename T>
void output1(const T &obj) {
    for(auto i = 0; i < obj.size(); ++i)
        cout << obj.at(i) << ", ";
    cout << "\b\b \n";
}

// 函数模板
// 通过迭代器方式输出对象值
template<typename T>
void output2(const T &obj) {
    for(auto p = obj.cbegin(); p != obj.cend(); ++p)
        cout << *p << ", ";
    cout << "\b\b \n";
}

// 函数模板
// 通过auto for方式输出对象值
template<typename T>
void output3(const T &obj) {
    for(auto &item: obj) 
        cout << item << ", ";
    cout << "\b\b \n";
}

// 测试string类对象
void test1() {
    string s1{"cplus"};

    output1(s1);

    reverse(s1.begin(), s1.end());  // 对对象s1中的数据项进行翻转
    output2(s1);

    sort(s1.begin(), s1.end());   // 对对象s1中的数据项排序(默认升序)
    output3(s1);
}

// 测试array<int>类对象
void test2() {
    array< array<int, 4>, 3> x{1, 9, 8, 4, 2, 0, 2, 2, 2, 0, 4, 9 };

    output1( x.at(0) );
    output2( x.at(1) );
    output3( x.at(2) );
}

// 测试vector<string>类对象
void test3() {
    vector<string> v1 {"Sheldon", "Leonard", "Howard", "Raj"};

    v1.push_back("Penny");
    v1.push_back("Amy");

    output1(v1);

    sort(v1.begin(), v1.end(), std::greater<string>());  // 对v1对象中的字符串按降序排序
    output2(v1);

    reverse(v1.begin(), v1.end());  // 对v1对象中的字符串翻转
    output3(v1);
}

int main() {
    cout << "test1: " << endl;
    test1();

    cout << "test2: " << endl;
    test2();

    cout << "test3: " << endl;
    test3();
}

测试截图

 

5.实验任务5

程序源码

info.hpp

#include<iostream>
#include<string>
#include<iomanip>

using namespace std;

class info{
public:
    info(string name,string contact,string city,int n);
    ~info()=default;
    
    void print();
    int get_total();
    
private:
    string nickname;
    string contact;
    string city;
    int n;
    static int total;
};

int info::total=0;
info::info(string name,string contact,string city,int n):nickname{name},contact{contact},city{city},n{n}{
    total+=n;
}

int info::get_total(){
    return total;
}

void info::print(){
    cout<<setw(10)<<"称呼:"<<nickname<<endl
        <<setw(10)<<"联系方式:"<<contact<<endl
        <<setw(10)<<"所在城市:"<<city<<endl
        <<setw(10)<<"预定人数:"<<n<<endl<<endl;
}

task5.cpp

#include"info.hpp"
#include<vector>
#include<iomanip>

using namespace std;

static int i=0;
const int capacity=100;

int main(){
    vector<info>audience_info_list;
    string name,contact,city;
    int n;
    char ch;
    
    cout<<"录入信息:"<<endl;
    cout<<std::left<<"昵称\t"
        <<"联系方式(邮箱/手机号)\t\t"
        <<"所在城市\t"
        <<"预定参加人数\t"<<endl;
    while(cin>>name)
    {
        cin>>contact
           >>city
           >>n;
        if(i+n<=capacity)
        {
            info t(name,contact,city,n);
            audience_info_list.push_back(t);
            i+=n;
            if(i==capacity)
            break;
        }
        else
        {
            cout<<"对不起,只剩"<<capacity-i<<"个位置."<<endl;
            cout<<"1.输入u,更新(update)预定信息"<<endl
                <<"2.输入q,退出预定"<<endl;
            cout<<"你的选择:";
            cin>>ch;
            if(ch=='u')
            cout<<"请重新录入信息:"<<endl;
            else
            {
                cout<<endl; 
                break;
            }            
        }
     } 
     cout<<endl;
     cout<<"截至目前,一共有"<<i<<"位听众预定参加。预定听众信息如下:"<<endl;
     for(auto list:audience_info_list)
     list.print(); 
}

测试截图

 

6.实验任务6

程序源码

textcoder.hpp

#include<iostream>
#include<string>

using namespace std;

class TextCoder{
public:
    TextCoder(string text);
    ~TextCoder()=default;
    
    string get_ciphertext();
    string get_deciphertext();
    
private:
    string text;
    void encoder();
    void decoder(); 
};

TextCoder::TextCoder(string text):text{text}{}

void TextCoder::encoder(){
    for(int i=0;i<text.length();i++)
    {
        if((text[i]>='f'&&text[i]<='z')||(text[i]>='F'&&text[i]<='Z'))
        {
            text[i]-=5;
        }
        else if((text[i]>='a'&&text[i]<='e')||(text[i]>='A'&&text[i]<='E'))
        {
            text[i]+=21;
        }
    }
}

void TextCoder::decoder()
{
    for(int i=0;i<text.length();i++)
    {
        if((text[i]>='a'&&text[i]<='u')||(text[i]>='A'&&text[i]<='U'))
        {
            text[i]+=5;
        }
        else if((text[i]>='V'&&text[i]<='Z')||(text[i]>='v'&&text[i]<='z'))
        {
            text[i]-=21;
        }
    }
}

string TextCoder::get_ciphertext(){
    encoder();
    return text;
}

string TextCoder::get_deciphertext(){
    decoder();
    return text;
}

task6.cpp

#include "textcoder.hpp"
#include <iostream>
#include <string>

void test() {
    using namespace std;

    string text, encoded_text, decoded_text;

    cout << "输入英文文本: ";
    while (getline(cin, text)) {
        encoded_text = TextCoder(text).get_ciphertext();  // 这里使用的是临时无名对象
        cout << "加密后英文文本:\t" << encoded_text << endl;

        decoded_text = TextCoder(encoded_text).get_deciphertext(); // 这里使用的是临时无名对象
        cout << "解密后英文文本:\t" << decoded_text << endl;
        cout << "\n输入英文文本: ";
    }
}

int main() {  
    test(); 
}

测试截图

 

posted @ 2022-10-21 14:47  阑夜风华  阅读(21)  评论(0编辑  收藏  举报