使用相应的数组对数组进行排序

Question

当前创建的一段代码能够从文本文件输出，我正在读取文本并将每条不同的信息放入数组中。

我已经使用了4个不同的数组，因为我想存储4种不同类型的信息。这个代码的工作方式和预期的一样，但我不确定如何按照字母顺序对数据进行排序，并且所有相应的数组都保持一致并在正确的时间输出。

void displayfile(){ 

string filename1; 
string rartist[NUM]; 
string rtitle[NUM]; 
string ryear[NUM]; 
string rcategory[NUM]; 
ifstream openFile; 
int counter = 0; 
int continu 
bool error = false; 
cout << "test"; 

do{ 
    //Loop to retrieve the file name from user, then open file 
    do{ 
     cout << "Please enter the name of the menu you would like to open: "; 
     cin >> filename1; 
     filename1 += ".txt"; 
     openFile.open(filename1.c_str()); 
     if(openFile.fail()){ 
      cerr << "Check spelling of file name.\n"; 
      error = true; 
     } 
    //Storing text from file into arrays 
    }while(error == true); 
    while(getline(openFile, rartist[counter], ':') && getline(openFile, rtitle[counter], ':') && 
     getline(openFile, ryear[counter], ':') && getline(openFile, rcategory[counter])){ 
    counter++; 
    } 
    //outputting the information stored in the array 
    cout << "ARTIST " << " DVDTITLE " << " YEAR " << " CATEGORY \n"; 
    for(int i = 0; i < counter; i++){ 
     cout << rartist[i] << "    " << rtitle[i] << "    " 
      << ryear[i] << "    " << rcategory[i] << "\n"; 
    } 
    cout << "\n\nIf you would like to read another file, Press 1: "; 
    cin >> continu; 
    }while(continu == 1) 
} 

这是我用来显示当前文本的功能。

Answer 1

我假设您正在阅读有关歌曲的信息，并且您想根据歌曲标题对其进行排序。由于您正在为每首歌曲读取相同类型的数据，因此请使用单个结构数组，而不是单独的数组。

例如，这是如何按歌名排序歌曲。

struct Song { 
    std::string artist, 
    std::string title, 
    std::string year, 
    std::string category 
}; 

std::vector<Song> songs(NUM); 

// Read data 

std::sort(songs.begin(), songs.end(), 
    [](const Song &a, const Song &b) { 
     return a.title < b.title; 
    }); 

Answer 2

完全未经测试C++ 11代码

std::vector<int> indexes(NUM); 
// fill with 0..NUM-1 
std::iota(indexes.begin(), indexes.end(), 0); 

// example sort after artist. 
std::sort(indexes.begin(), indexes.end(), 
    [&rartist](const int &lhs, const int &rhs) { 
     return rartist[lhs] < rartist[rhs]; 
    }); 
// indexes is now sorted in the same way rartist would have been. 

// now iterate in order. 
for (int i : indexes) { 
    std::cout << rartist[i] << "    " 
       << rtitle[i] << "    " 
       << ryear[i] << "    " 
       << rcategory[i] << "\n"; 
}