一、实验目的
- 知道什么是类模板，会正确定义和使用简单的类模板
- 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
- 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
- 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
- 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
- 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
二、实验内容
实验任务1
程序代码
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();
}
结果截图
task1_1.cpp
task1_2.cpp
实验任务2
程序代码
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{"[email protected]"};
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); // 浜ゆ崲
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;
}
结果截图
task2_1.cpp
task2_2.cpp
实验任务5
程序代码
info.hpp
#pragma once
#include<iostream>
#include<iomanip>
#include<string>
using namespace std;
class info
{
private:
string nickname, contact, city;
int n;
public:
info(string nknm, string cnt, string ct, int n): nickname{nknm}, contact{cnt}, city{ct}, n{n}{}
void print();
// void set_nickname(){getline(cin, nickname);}
// void set_contact(){getline(cin, contact);}
// void set_city(){getline(cin, city);}
// void set_n(){cin >> n;}
// int get_n(){return n;}
};
void info::print()
{
cout << setfill(' ') << setw(8) << left << "昵称: " << nickname << endl
<< setfill(' ') << setw(8) << left << "联系方式: " << contact << endl
<< setfill(' ') << setw(8) << left << "所在城市: " << city << endl
<< setfill(' ') << setw(8) << left << "预定人数: " << n << endl;
cout << endl;
}
task5.cpp
#include "info.hpp"
#include<iostream>
#include<iomanip>
#include<vector>
#include<string>
using namespace std;
const int capacity = 100;
vector<info> audience_info_list;
void test()
{
cout << "录入信息：\n" << endl;
cout << 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;
int count = 0;
string s1, s2, s3;
int n1;
while(cin >> s1 >> s2 >> s3 >> n1)
{
audience_info_list.push_back(info(s1, s2, s3, n1));
count += n1;
// audience_info_list[i].set_nickname();
// audience_info_list[i].set_contact();
// audience_info_list[i].set_city();
// audience_info_list[i].set_n();
// count += audience_info_list[i].get_n();
if(count > capacity)
{
count -= n1;
cout << "对不起, 只剩" << capacity - count << "个位置" << endl
<< "1. 输入u, 更新预定信息" << endl
<< "2. 输入q, 退出预定" << endl
<< "你的选择: ";
char s;
cin >> s;
if( s == 'q')
{
break;
}
else if ( s == 'u')
{
continue;
}
}
else if (count == capacity)
{
break;
}
}
cout << "截至目前，一共有" << count << "位听众预定参加。预定听众信息如下：" << endl;
// for(auto &item: audience_info_list)
// {
// item.print();
// }
for (auto &item : audience_info_list)
{
item.print();
}
}
int main()
{
test();
}
结果截图
结果1
结果2
实验任务6
程序代码
TextCoder.hpp
#pragma once
#include<iostream>
#include<string>
using namespace std;
class TextCoder
{
private:
string text;
void encoder();
void decoder();
public:
TextCoder(string t);
string get_ciphertext();
string get_deciphertext();
~TextCoder() = default;
};
TextCoder::TextCoder(string t1): text{t1}{}
void TextCoder::encoder()
{
for(int i = 0; i < text.length(); i++)
{
if((text[i] >= 97 && text[i] <= 122) || (text[i] >= 65 && text[i] <= 90))
{
if (text[i] + 5 > 122 || (text[i] + 5 > 90 && text[i] + 5 < 97))
{
text[i] -= 21;
}
else
{
text[i] += 5;
}
}
else
{
continue;
}
}
}
void TextCoder::decoder()
{
for(int i = 0; i < text.length(); i++)
{
if((text[i] >= 97 && text[i] <= 122) || (text[i] >= 65 && text[i] <= 90))
{
if (text[i] - 5 < 65 || (text[i] - 5 > 90 && text[i] - 5 < 97))
{
text[i] += 21;
}
else
{
text[i] -= 5;
}
}
else
{
continue;
}
}
}
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();
}
结果截图
更改数据测试
