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大家好，我对 C++ 并不陌生，但我的技能不是很熟练。无论如何，我有一个任务我无法按时完成，而且我无法让我的代码工作真的让我很烦恼。现在我只想完成它，这样我就可以知道未来的任务该怎么做。

数据文件在同一行包含玩家的数量和他们的分数，最后一列是他们的时间。

问题是这样的，我必须在我的程序中打开一个 .txt 文件，它的内容如下（没有项目符号）。

  • 27
  • 流行音乐 23 45 92 34 43 125
  • 警察 4 23 56 23 75 323
  • ……等等。

如何存储/忽略第一个变量，然后逐列（以空格分隔）创建包含数据的数组？

这是我创建的。我已经创建了需要将相应数据存储到其中的数组。

#include <iostream>
#include <cmath>
#include <ctime>
#include <iomanip>
#include <vector>
#include <string>
#include <sstream>
#include <fstream>
using namespace std;

int main()
{
    cout<<"Welcome to the Score Sorting Program! \n";
    cout<<"Please choose a number that corresponds with the way you would like to  sort. \n";
    cout<<"You may also search by player if you know their username. \n";

    string players[50]; //Allocated space for 50 players.
    int score1[27]; //Array for Score 1
    int score2[27]; //
    int score3[27]; //
    int score4[27]; //
    int score5[27]; //
    int time[27];   //Array for Time
    int i = 0;
    int j = 0;

    ifstream myfile;
    myfile.open("G2347M.txt");
    if (!myfile)
    {
         cout<<"Could not open file. \n";
         system ("Pause");
         return -1;
    }  

    while (!myfile.eof())
    {
        getline(myfile, players[i], ' ');
        if (i == 26)
        {
            i=0;
            ++j;
            getline(myfile, players[i],' ');
        }
        i++;
    }    

}

所以基本上我会将玩家与他们的分数对齐并输出到另一个文件。我只想读入文件的第一部分，然后继续。

我研究了类似的主题（4 小时以上），试图拼凑代码让我的工作。我将继续研究并尽我所能进行更新。

4

3 回答 3

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为什么50个球员却只有27个分数？

我假设第一行是您希望阅读的总行数？如果是这样，您可以动态分配数组来保存所有数据，而不仅仅是处理 50 行（或者是 27 行）。您还可以将一行的所有数据组合到一个结构中，而不是将其分布在一堆不连贯的数组中。

伪代码：

int lineNo = 1;
int totalLines = -1; /* not set */

while(line = read_a_line()) {
    if (lineNo == 1) {
        totalLines = convert_line_text_to_number();
    }
    else {
        /* split the line into "tokens" separated by white space */
        /* store each token in the correct array */
    }
    lineNo++;
    /* if lineNo is too big, break the loop */
}
于 2013-06-20T03:48:54.160 回答
0

使用它的最佳方法是使用向量。但是正如您所说，您一定会使用数组，所以这里是它的代码。

#include <iostream>
#include <fstream>
#include <sstream>

using namespace std;

int main()
{
    ifstream file;
    file.open("sample.txt");

    string name[50];
    int score1[27],score2[27],score3[27],score4[27],score5[27],time[27];


    int i = 0;
    while(!file.eof())
    {
        string line;
        getline(file,line);
        char* a = const_cast<char*>(line.c_str());  
        char* pch = strtok (a," ");

        name[i] = pch;
        int counter = 1;
        while (counter < 7)
        {
            pch = strtok (NULL, " ");

            if(counter == 1)
            {
                score1[i] = atoi(pch);
            }
            else if(counter == 2)
            {
                score2[i] = atoi(pch);
            }
            else if(counter == 3)
            {
                score3[i] = atoi(pch);
            }
            else if(counter == 4)
            {
                score4[i] = atoi(pch);
            }
            else if(counter == 5)
            {
                score5[i] = atoi(pch);
            }
            else if(counter == 6)
            {
                time[i] = atoi(pch);
            }

            ++counter;
        }

        ++i;
    }

    //cout<<a;
    return 0;
}

如果您遇到任何问题，请告诉我。我没有添加一些基本的健全性检查，例如文件检查，请在您的版本中执行此操作。

于 2013-06-20T05:35:55.037 回答
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这是一种使用运算符>>的封装和重载的方法。我假设您所描述的输入只是一长串以空格分隔的输入值，第一个值是玩家人数。

#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <fstream>
#include <ctype.h>

using namespace std;

static const size_t MaxNumPlayers = 50;

// C++ is about encapsulation, and the player data is
// discrete yet related, so encapsulate it.
struct Player
{
    string m_name;
    int m_scores[5];
    size_t GetNumScores() const { return sizeof(m_scores) / sizeof(m_scores[0]); }
    int m_time;
};

// This allows us to write an operator that will read a player
// directly from an ifstream.
std::ifstream& operator>>(ifstream& istr, Player& player)
{
    istr >> player.m_name;
    for(size_t i = 0; i < player.GetNumScores(); ++i)
    {
       istr >> player.m_scores[i];
    }
    istr >> player.m_time;
    cout << "player: " << player.m_name << ", " << player.m_scores[0] << " @ " << player.m_time << endl;
    return istr;
}

int main(int argc, const char** argv)
{
    ifstream myfile("G2347M.txt");
    if (!myfile)
    {
         cout<<"Could not open file. \n";
         system("Pause");
         return -1;
    }

    // We can read the number of players directly.
    size_t numPlayers = 0;
    myfile >> numPlayers;
    if (numPlayers <= 0 || numPlayers > MaxNumPlayers) {
        cout << "Invalid number of players in score file ("<<numPlayers<<")." << endl;
        system("Pause");
        return -1;
    }

    Player players[MaxNumPlayers];
    size_t playersRead = 0;

    while (!myfile.eof())
    {
        myfile >> players[playersRead++];
        if (playersRead >= numPlayers)
            break;
        // drain any spaces after the player.
        while(isspace(myfile.peek()))
          myfile.ignore();
    }

    if (playersRead != numPlayers)
    {
        cout << "Problem reading score file, expected " << numPlayers << " but read " << playersRead << endl;
        system("Pause");
        return -1;
    }

    cout<<"Welcome to the Score Sorting Program! I read "<<playersRead<<" players."<<endl;
    cout<<"Please choose a number that corresponds with the way you would like to sort."<<endl;
    cout<<"You may also search by player if you know their username.\n"<<endl;

    /* ... */

    system("Pause");
    return 0;
}
于 2013-06-20T05:38:25.440 回答