c++ - 按顺序显示字符串 - 练习题

Question

所以，我目前正在阅读 Bjarne Stroustrup 的“编程:使用 C++ 的原理和实践”，我正在阅读第 3 章。书中有一个问题是“编写一个程序，提示用户输入 3 个字符串值，然后按逗号分隔的顺序输出值。因此，如果用户输入值“Steinbeck”、“Hemingway”、“Fitzgerald”，则输出应为“Fitzgerald、Hemingway、Steinbeck”。

我目前被困在那个问题上，我似乎无法使该程序运行。我知道如何按数字序列输出整数，就像这段代码 http://www.stroustrup.com/Programming/Solutions/Ch3/e3-6.cpp但我似乎无法修改它以使其使用字符串值(我收到错误“ fatal error LNK1120:1 个 Unresolved external ”，我希望了解如何这样做。

感谢任何帮助。

ps:这是链接中内容的修改代码(这是我回答问题的蹩脚尝试)。我知道有更简单的方法可以做到这一点，但我还没有，它在下一章( vector )中:

#include "D:\Mes Documents\Visual Studio 2010\std_lib_facilities.h"

int main()
{
    string name1 = " ";
    string name2 = " ";
    string name3 = " ";

    cout << "Please enter three names seperated by spaces: " << endl;
    cin >> name1 >> name2 >> name3;
    if (!cin) error("Something went wrong with the read");

    string smallest = " ";
    string middle = " ";
    string biggest = " ";

    if (name1<=name2 && name1<=name3)
    {
        smallest = name1;
        if (name2<=name3)
        {
            middle = name2;
            biggest = name3;
        }
        else
        {
            middle = name3;
            biggest = name2;
        }
    }
    else if (name2<=name1 && name2<=name3)
    {
        smallest = name2;
        if (name1<=name3)
        {
            middle = name1;
            biggest = name3;
        }
        else
        {
            middle = name3;
            biggest = name1;
        }
    }
    else
    {
        smallest = name3;
        if (name1<=name2)
        {
            middle = name1;
            biggest = name2;
        }
        else
        {
            middle = name2;
            biggest =name1;
        }
    }

    cout << "The names in order are: " << smallest << " " << middle << " " << biggest << endl;

    system("pause");
    return 0;
}

Answer 1

以这种方式解决了 #6 - 与任务要求的有点不同。稍后将更正并在此处发布 3.7 的解决方案。

#include "../../std_lib_facilities.h"
int main()
{
    cout << "Enter three integers:\n";
    int a = 0;
    int b = 0;
    int c = 0;
    cin >> a >> b >> c;
    if (a == b)
    {
        if (b == c)
        {
            cout << '\n' << a << " = " << b << " = " << c;
        }
        else if (a > c)
        {
            cout << '\n' << a << " = " << b << " > " << c;
        }
        else if (a < c)
        {
            cout << '\n' << c << " > " << a << " = " << b;
        }
    }
    else if (a == c)
    {
        if (a > b)
        {
            cout << '\n' << a << " = " << c << " > " << b;
        }
        else if (a < b)
        {
            cout << '\n' << b << " > " << a << " = " << c;
        }
    }
    else if (b == c)
    {
        if (b > a)
        {
            cout << '\n' << b << " = " << c << " > " << a;
        }
        else if (b < a)
        {
            cout << '\n' << a << " > " << b << " = " << c;
        }
    }
    else if (a > b)
    {
        if (a > c)
        {
            if (b > c)
            {
                cout << '\n' << a << " > " << b << " > " << c;
            }
            else if (c > b)
            {
                cout << '\n' << a << " > " << c << " > " << b;
            }
        }
        else if (a < c)
        {
            cout << '\n' << c << " > " << a << " > " << b;
        }
    }
    else if (b > a)
    {
        if (b > c)
        {
            if (a > c)
            {
                cout << '\n' << b << " > " << a << " > " << c;
            }
            else if (c > a)
            {
                cout << '\n' << b << " > " << c << " > " << a;
            }
        }
        else if (b < c)
        {
            cout << '\n' << c << " > " << b << " > " << a;
        }
    }
}