实验目的

1. 知道什么是类模板，会正确定义和使用简单的类模板
2. 能够描述数组的特性，会使用C++语法正确定义和访问内置数组，知道其局限性
3. 能够解释指针变量的特性，会使用C++语法正确定义指针变量间接访问对象
4. 能熟练使用现代C++标准库中的数组模板类array、动态数组类模板vector、字符串类string
5. 知道现代C++标准库中迭代器，会使用迭代器访问各种序列容器对象
6. 针对具体问题场景，能够灵活、组合使用C++标准库与自定义类对问题进行抽象和编程求解

实验内容

5.实验任务5

实验代码

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

class Info
{
private:
    string nickname;
    string contact;
    string city;
    int number;

public:
    Info(string, string, string, int);
    void print();
};
Info::Info(string Name = {}, string Contact = {}, string City = {}, int n = 0) : nickname{Name}, contact{Contact}, city{City},number{n}{}
void Info::print()
{
    cout << setfill(' ') << setw(16) << left << "昵称:" << nickname << endl
         << setfill(' ') << setw(16) << left << "联系方式:" << contact << endl
         << setfill(' ') << setw(16) << left << "所在城市:" << city << endl
         << setfill(' ') << setw(16) << left << "预定人数:" << number << endl
         << endl;
}
int Number=0;
int main(int argc, char const *argv[])
{
    const int capacity = 100;
    vector<Info> audience_info_list;
    int n;
    string s, s1, s2, s3;
    cout << "录入信息：" << endl
         << endl
         << setfill(' ') << setw(16) << left << "昵称"
         << setfill(' ') << setw(28) << left << "联系方式(邮箱/手机号)"
         << setfill(' ') << setw(16) << left << "所在城市"
         << setfill(' ') << setw(16) << left << "预定参加人数" << endl;
    while (cin >> s1)
    {
        cin >> s2 >> s3 >> n;
        audience_info_list.push_back(Info(s1, s2, s3, n));
        Number+=n;
        if (Number > capacity)
        {
            Number-=n;
            cout << "对不起，只剩" << capacity - Number << "个位置。" << endl
                 << "1.输入u,更新(update)预定信息" << endl
                 << "2.输入q,退出预定" << endl
                 << "你的选择：";
            cin >> s;
            if (s == "q")
            {
                break;
            }
            if (s == "u")
            {
                audience_info_list.pop_back();
                continue;
            }
        }
    }
    cout <<endl<< "截止目前，一共有" << Number << "位听众预定参加。预定听众信息如下：" << endl;
    for (auto &item : audience_info_list)
    {
        item.print();
    }
    return 0;
}

测试结果

6.实验任务6

实验代码

textcoder.hpp

#pragma once

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

class TextCoder
{
private:
    string text;

public:
    TextCoder(string);
    string get_ciphertext();
    string get_deciphertext();

private:
    void encoder(string &s)
    {
        for (auto &i : s)
        {
            if (isalpha(i))
            {
                i += 5;
                if (i > 'z'||i<'a'&&i>'Z')
                i -= 26;
            }
        }
    }
    void decoder(string &s)
    {
        for (auto &i : s)
        {
            if (isalpha(i))
            {
                i -= 5;
                if (i < 'A'||i>'Z'&&i<'a')
                i += 26;
            }
        }
    }
};

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

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

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

task6.cpp

#pragma once

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

class TextCoder
{
private:
    string text;

public:
    TextCoder(string);
    string get_ciphertext();
    string get_deciphertext();

private:
    void encoder(string &s)
    {
        for (auto &i : s)
        {
            if (isalpha(i))
            {
                i += 5;
                if (i > 'z'&&i>'Z')
                i -= 26;
            }
        }
    }
    void decoder(string &s)
    {
        for (auto &i : s)
        {
            if (isalpha(i))
            {
                i -= 5;
                if (i > 'z'&&i>'Z')
                i += 26;
            }
        }
    }
};

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

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

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

测试结果

1.实验任务1

实验代码

task1_1.cpp

#include <iostream>

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

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

// 类B的定义
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();
}

task1_2.cpp

#include <iostream>
#include <string>

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

// 定义类模板X
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();
}

测试结果

2.实验任务2

实验代码

task2_1.cpp

#include <iostream>
#include <string>

int main() {
    using namespace std;

    string s1, s2;
    s1 = "nuist";                                 // 赋值
    s1[0] = 'N';                                  // 支持通过[]和索引方式访问
    s1.at(1) = 'U';                               // 支持通过xx.at()方法访问
    cout << boolalpha << (s1 == "nuist") << endl; // 字符串比较
    cout << s1.length() << endl;                  // 字符串长度
    cout << s1.size() << endl;                    // 字符串长度
    s2 = s1 + ", 2050";                           // 字符串连接
    cout << s2 << endl;

    string email{"xyz@gmail.com"};
    auto pos = email.find("@"); // 查找子串"@"第一次出现的索引位置，如果失败，返回string::npos
    if (pos == string::npos)
        cout << "illegal email address";
    else {
        auto s1 = email.substr(0, pos);  // 取子串, 从索引0 ~ pos-1
        auto s2 = email.substr(pos + 1); // 取子串，从pos+1到末尾
        cout << s1 << endl;
        cout << s2 << endl;
    }

    string phone{"15216982937"};
    cout << phone.replace(3, 5, string(5, '*')) << endl; // 把从索引位置为3开始的连续5个字符替换成*

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

    string s5{"abc"};
    const char *pstr = s5.c_str(); // 方法c_str()把string类字符串组转换成C风格的字符串
    cout << pstr << endl;

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

    int x2 = 12306;
    string s7 = to_string(x2);  // 把int转换成string
    cout << s7 << endl;

    double x3 = 123.06;
    string s8 = to_string(x3); // 把double转换成string
    cout << s8 << endl;
}

task2_2.cpp

#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;
}

task2_3.cpp

#include <iostream>
#include <string>

int main() {
    using namespace std;

    string s;

    cout << "Enter words: \n";
    // 重复录入字符串，将小写字符转换成大写，直到按下Ctrl+Z
    while( getline(cin, s) ) {
        for(auto &ch: s)
            ch = toupper(ch);
        cout << s << "\n";
    }
}

task2_4.cpp

#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;
}

测试结果

3.实验任务3

实验代码

task3_1.cpp

#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);
    return 0;
}

task3_2.cpp

#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);
    return 0;
}

测试结果

4.实验任务4

实验代码

#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();
    return 0;
}

测试结果

原文地址：http://www.cnblogs.com/PhantomGmc/p/16803792.html