实验3 数组、指针与现代C++标准库

实验任务五：

Info.hpp:

#pragma once
#include<iostream>
#include<string>
#include<iomanip>

using namespace std;

class Info {
private:
    string nickname, contact, city;
    int n;

public:
    Info(string a, string b, string c, int d) :nickname{ a }, contact{ b }, city{ c }, n{ d }{}
    ~Info() = default;
    void print()const;
};


void Info::print()const {
    
    cout << left << setw(7) << "昵称：" << nickname << endl;
    cout << left << setw(7) << "联系方式：" << contact << endl;
    cout << left << setw(7) << "所在城市：" <<city << endl;
    cout << left << setw(7) << "预定人数：" <<n << endl;
    cout << endl;
}

task5.cpp:

#include"Info.hpp"
#include<iostream>
#include<string>
#include<vector>
#include<iomanip>


int main()
{
    using namespace std;
    const int capacity = 100;
    vector<Info> audience_info_list;
    string s1, s2, s3;
    char ch;
    int m;
    static int count;
    count = 0;
    cout << "录入信息：\n\n" << "昵称   " << "联系方式（邮箱/手机号）   " << "所在城市       " << "预定参加人数" << endl;
    while (cin >> s1) {
        cin >> s2 >> s3 >> m;
        if (count + m < capacity)
        {
            Info aud(s1, s2, s3, m);
            audience_info_list.push_back(aud);
            count += m;
            if (m == capacity)
                break;
        }
        else
        {
            int left = capacity - count ;
            cout << "对不起，只剩" << left << "个位置。" << endl;
            cout << "1.输入u，更新（update）预定信息。" << endl;
            cout << "2.输入q，退出预定。" << endl;
            cout << "你的选择：";
            cin >> ch;
            if (ch == 'q')
            {
                cout << endl;break;
            }
            else continue;
        }
    }
        cout << "截至目前，一共有" << count << "位听众预定参与。预定听众信息如下：" << endl;
        for (auto item : audience_info_list)
        {
            item.print();
        }
    
}

当听众在限制人数内的测试结果：

当听众人数超载的测试结果：

实验任务六：

TextCoder.hpp:

#pragma once
#include<iostream>
#include<string>

using namespace std;

class TextCoder {
private:
    string text;
    void encoder()
    {
        for (auto i = 0;i < size(text);++i)
            if (isalpha(text.at(i)))
            {
                if ((text.at(i) >= 'v'&&text.at(i)<='z' )||(text.at(i)<='Z'& text.at(i) >= 'V'))
                    text.at(i) -= 21;
                else
                    text.at(i) += 5;
            }
    }
    void decoder()
    {
        for (auto i = 0;i < size(text);++i)
            if (isalpha(text.at(i)))
            {
                if ((text.at(i) <= 'e'&&text.at(i)>='a') || (text.at(i)>='A'&&text.at(i) <= 'E'))
                    text.at(i) += 21;
                else
                    text.at(i) -= 5;
            }
    }
public:
    TextCoder(string t):text{t}{}
    ~TextCoder() = default;
    string get_ciphertext() { encoder();return text; }
    string 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();

        cout << "加密后英文文本:\t" << encoded_text << endl;

        decoded_text = TextCoder(encoded_text).get_deciphertext();

        cout << "解密后英文文本:\t" << decoded_text << endl;
        cout << "\n输入英文文本：";
    }
}

int main()
{
    test();
}

测试结果：

实验总结：

双引号赋值一个字符串；
s[i]访问第i+1个字符；由此可见，string是类似数组的容器 ；
s.at(i)访问；
boolalpha<<(s=="nuist")字符串比较，false和true
s.length(),s.size()字符串长度；
auto pos=s.email("c")查找子串第一次出现的索引位置，失败返回string::nops;
s.substr(0,pos)，s.substr(pos+1)取子串