Question

我试图创建一个程序，从用户那里获取一个字符串，搜索一个2D数组，如果它匹配数组中的字符串，则打印整行。所以基本上，如果用户输入名称Bobby G，我希望输出Bobby G: ugly and stupid，如果输入为Billy则输出Billy: bad，依此类推等等。以下是我到目前为止的情况。我们将非常感谢您的一些解释。

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

using namespace std;

int main()  {

//!! It only works with letters of the alphabet, so if I replaced Bobby G with the  
//letter "A" It would output "ugly, and stupid", and then replace "Billy Smalls" with
//the letter "B" I'd get "Bad" so on and so forth, but I need it to work with the exact
// string, so user input of "Bobby G" outputs "ugly, and stupid"
std::string name[9][2] = {        
    {"Bobby G","ugly, and stupid"},
    {"Billy","bad"},
    {"John","smart and cool"},
    {"Adam","amzing and beautiful"},
    {"Bill","perfect"},
    {"Turner","funny"},
    {"Sonny","nice"},
    {"Jack","radical"},
    {"Frank","nice"}};

typedef std::string Full[2];

Full* last_Full = name + sizeof(name) / sizeof(Full);

struct Less {
    bool operator () (const Full& a, const string& b) const 
        {
        return a[0] < b;
        }
            };
std::string input;
std::cin >> input;

Less less_full;

Full* full = std::lower_bound(name, last_Full, input, less_full);

    if(full == last_Full || (*full)[0] != input) 
    std::cout << "Not found" << std::endl;

else std::cout << (*full)[0] << ": " << (*full)[1]  << std::endl;

system("Pause");
return 0;
}

我想在没有嵌套if语句并使其变得混乱的情况下这样做。

Answer 1

我真的很难理解你在代码中写的内容，但根据描述，这应该类似于（demo）：

#include <iostream>
#include <unordered_map>
#include <string>

int main(void) {
    std::unordered_map<std::string, std::string> name = {        
    {"Bobby G","ugly, and stupid"},
    {"Billy","bad"},
    {"John","smart and cool"},
    {"Adam","amzing and beautiful"},
    {"Bill","perfect"},
    {"Turner","funny"},
    {"Sonny","nice"},
    {"Jack","radical"},
    {"Frank","nice"}};

    std::string in;
    std::getline(std::cin,in);
    if(name.count(in)){
        std::cout << in << " " << name[in] << std::endl;
    }
    return 0;
}

为了避免让我们头疼，将来缩进你的代码并且不要让它看起来像ASCII艺术...

所以基本上我们使用的是unordered_map，它将名称作为键，将句子作为值。

然后我们使用cin接收用户的输入并将其放入string in。

最后一步是使用count检查地图中是否有这样的字符串作为键，如果它包含此键，则会返回1。

但严重的是，你必须更认真地阅读;找到一本教程和/或一本书，直接理解你的观点。

Answer 2

任务并不像看起来那么简单。所以我向你投了你的问题。

首先，最好使用类型std::pair<std::string, std::string>的一维数组，而不是您使用的二维数组。其次，要应用算法std::lower_bound，必须对数组进行排序。

代码可以采用以下方式

#include <iostream>
#include <algorithm>
#include <iterator>
#include <string>
#include <utility>
#include <cctype>


int main()
{
    std::pair<std::string, std::string> name[] = 
    {        
        { "Bobby G", "ugly, and stupid" },
        { "Billy", "bad" },
        { "John", "smart and cool" },
        { "Adam", "amzing and beautiful" },
        { "Bill", "perfect" },
        { "Turner", "funny" },
        { "Sonny", "nice" },
        { "Jack", "radical" },
        { "Frank", "nice" }
    };

    std::sort( std::begin( name ), std::end( name ) );

    auto compare_by_name = 
    []( const std::pair<std::string, std::string> &p1, 
        const std::pair<std::string, std::string> &p2 )
    {
        return std::lexicographical_compare( 
            p1.first.begin(), p1.first.end(), 
            p2.first.begin(), p2.first.end(),
            []( char c1, char c2 ) 
            { return std::toupper( c1 ) < std::toupper( c2 ); } );
    };

    auto p = std::make_pair( std::string( "bobby g" ), std::string( "" ) );
    auto it = std::equal_range( std::begin( name ), std::end( name ), p,
                                compare_by_name );

    if ( it.first != it.second )
    {
        std::cout << it.first->first + ' ' + it.first->second << std::endl;
    }

    return 0;
}

输出

Bobby G ugly, and stupid

关于那些拒绝投票你的问题的参与者。：）

如果编译器发出相对于数组初始值设定项的错误，则应使用以下方法替换它们。例如

std::pair<std::string, std::string>( "Bobby G", "ugly, and stupid" ),

以下是使用其他类型初始化程序的代码

#include <iostream>
#include <algorithm>
#include <iterator>
#include <string>
#include <utility>
#include <cctype>


int main()
{
    std::pair<std::string, std::string> name[] = 
    {        
        std::pair<std::string, std::string>( "Bobby G", "ugly, and stupid" ),
        std::pair<std::string, std::string>( "Billy", "bad" ),
        std::pair<std::string, std::string>( "John", "smart and cool" ),
        std::pair<std::string, std::string>( "Adam", "amzing and beautiful" ),
        std::pair<std::string, std::string>( "Bill", "perfect" ),
        std::pair<std::string, std::string>( "Turner", "funny" ),
        std::pair<std::string, std::string>( "Sonny", "nice" ),
        std::pair<std::string, std::string>( "Jack", "radical" ),
        std::pair<std::string, std::string>( "Frank", "nice" )
    };

    std::sort( std::begin( name ), std::end( name ) );

    auto compare_by_name = 
    []( const std::pair<std::string, std::string> &p1, 
        const std::pair<std::string, std::string> &p2 )
    {
        return std::lexicographical_compare( 
            p1.first.begin(), p1.first.end(), 
            p2.first.begin(), p2.first.end(),
            []( char c1, char c2 ) 
            { return std::toupper( c1 ) < std::toupper( c2 ); } );
    };

    auto p = std::make_pair( std::string( "bobby g" ), std::string( "" ) );
    auto it = std::equal_range( std::begin( name ), std::end( name ), p,
                                compare_by_name );

    if ( it.first != it.second )
    {
        std::cout << it.first->first + ' ' + it.first->second << std::endl;
    }

    return 0;
}

您可以引入一些typedef名称，而不是使用长类型名称std::pair<std::string, std::string>，例如

typedef std::pair<std::string, std::string> Pair;

这是要求用户输入名称的程序

#include <iostream>
#include <algorithm>
#include <iterator>
#include <string>
#include <utility>
#include <cctype>


int main()
{
    std::pair<std::string, std::string> name[] = 
    {        
        std::pair<std::string, std::string>( "Bobby G", "ugly, and stupid" ),
        std::pair<std::string, std::string>( "Billy", "bad" ),
        std::pair<std::string, std::string>( "John", "smart and cool" ),
        std::pair<std::string, std::string>( "Adam", "amzing and beautiful" ),
        std::pair<std::string, std::string>( "Bill", "perfect" ),
        std::pair<std::string, std::string>( "Turner", "funny" ),
        std::pair<std::string, std::string>( "Sonny", "nice" ),
        std::pair<std::string, std::string>( "Jack", "radical" ),
        std::pair<std::string, std::string>( "Frank", "nice" )
    };

    std::sort( std::begin( name ), std::end( name ) );

    auto compare_by_name = 
    []( const std::pair<std::string, std::string> &p1, 
        const std::pair<std::string, std::string> &p2 )
    {
        return std::lexicographical_compare( 
            p1.first.begin(), p1.first.end(), 
            p2.first.begin(), p2.first.end(),
            []( char c1, char c2 ) 
            { return std::toupper( c1 ) < std::toupper( c2 ); } );
    };

    while ( true )
    {
        std::cout << "Enter name: ";
        std:: string s;
        std::getline( std::cin, s );

        if ( s.empty() ) break;

        auto p = std::make_pair( s, std::string( "" ) );
        auto it = std::equal_range( std::begin( name ), std::end( name ), p,
                                    compare_by_name );

        if ( it.first != it.second )
        {
            std::cout << it.first->first + ' ' + it.first->second << std::endl;
        }
        else
        {
            std::cout << "The name is not found" << std::endl;
        }
    }

    return 0;
}

祝你好运。

获取用户输入并搜索2D阵列

2 个答案: