正在将txt文件读取到链接列表中

Reading from txt file into a linked list

本文关键字:链接 列表 读取 文件 txt      更新时间:2023-10-16

我正试图将*.txt文件中的数据读取到链接列表中。该文件由16种不同类型的数据组成,这些数据排列成行,每种数据类型之间都有选项卡。我对此有几个问题。编译器没有给出任何错误,但当我运行程序并输入要读取的文件名时,什么都不会发生。我试着用for循环for(int i=0; i<NUM_LINES; i++)替换while(!din.eof())行(下面的第27行),这似乎有帮助,但我得到了前三个元素(所有字符串类型),后面跟着一行零,这一行一直重复到循环结束。我已经包含了我认为问题所在的方法。我想知道是否有人可以看看我的代码,让我知道问题出在哪里。谢谢。

#include <iostream>
#include <fstream>
using namespace std;
class Node
{
 public:
   // Constructors
   Node();
   Node(const string name, const string position, const string team, const int g, const int att, const float attg, const int cmp, const float pct, const int yds, const float ydsg, const int lng, const int td, const int inte, const int sck, const int sckyl, const float rating);
   Node(const Node & node);
   ~Node();
   // Methods
   bool readData();
   void setNext(Node* next);
   void print() const;
 private:
   string Name;
   string Position;
   string Team;
   int G;
   int Att;
   float AttG;
   int Cmp;
   float Pct;
   int Yds;
   float YdsG;
   int Lng;
   int TD;
   int Int;
   int Sck;
   int SckYL;
   float Rating;
   Node *Next;
};
//----------------------------------------------
// Constructor method
//----------------------------------------------
Node::Node()
{
   Name = "";
   Position = "";
   Team = "";
   G = 0;
   Att = 0;
   AttG = 0.0;
   Cmp = 0;
   Pct = 0.0;
   Yds = 0;
   YdsG = 0.0;
   Lng = 0;
   TD = 0;
   Int = 0;
   Sck = 0;
   SckYL = 0;
   Rating = 0.0;
   Next = NULL;
}
//----------------------------------------------
// Constructor method with parameters
//----------------------------------------------
Node::Node(const string name, const string position, const string team, const int g, const int att, const float attg, const int cmp, const float pct, const int yds, const float ydsg, const int lng, const int td, const int inte, const int sck, const int sckyl, const float rating)
{
   Name = name;
   Position = position;
   Team = team;
   G = g;
   Att = att;
   AttG = attg;
   Cmp = cmp;
   Pct = pct;
   Yds = yds;
   YdsG = ydsg;
   Lng = lng;
   TD = td;
   Int = inte;
   Sck = sck;
   SckYL = sckyl;
   Rating = rating;
   Next = NULL;
}
//----------------------------------------------
// Copy constructor method
//----------------------------------------------
Node::Node(const Node & node)
{
   Name = node.Name;
   Position = node.Position;
   Team = node.Team;
   G = node.G;
   Att = node.Att;
   AttG = node.AttG;
   Cmp = node.Cmp;
   Pct = node.Pct;
   Yds = node.Yds;
   YdsG = node.YdsG;
   Lng = node.Lng;
   TD = node.TD;
   Int = node.Int;
   Sck = node.Sck;
   SckYL = node.SckYL;
   Rating = node.Rating;
   Next = NULL;
}
//----------------------------------------------
// Destructor method
//----------------------------------------------
Node::~Node()
{
}
//----------------------------------------------
// Method:   readData
// Purpose:  Read data from file into linked list, and print contents of the list.
//----------------------------------------------
bool Node::readData()
{
   // Declare local variables
   string name, position, team;
      name = position = team = "";
   int g, att, cmp, yds, lng, td, inte, sck, sckyl;
      g = att = cmp = yds = lng = td = inte = sck = sckyl = 0;
   float attg, pct, ydsg, rating;
      attg = pct = ydsg = rating = 0.0;
   // Get file name
   string filename = "";
   cout << "Enter file name: ";
   cin >> filename;
   // Open input file
   ifstream din;
   din.open(filename.c_str());
   if (din.fail())
   {
      cerr << "Could not open file: " << filename << endl;
      return false;
   }
   // Read data
   Node *head = NULL;
   while (!din.eof())
   {
      din >> name >> position >> team >> g >> att >> attg >> cmp >> pct >> yds >> ydsg >> lng >> td >> inte >> sck >> sckyl >> rating;
      Node *temp = new Node(name, position, team, g, att, attg, cmp, pct, yds, ydsg, lng, td, inte, sck, sckyl, rating);
      temp->setNext(head);
      head = temp;
   }
   din.close();
   head->print();
   return true;
}
//----------------------------------------------
// setNext method
//----------------------------------------------
void Node::setNext(Node* next)
{
   Next = next;
}
//----------------------------------------------
// Print method
//----------------------------------------------
void Node::print() const
{
   cout << Name << "    " << Position << "    " << Team << "    " << G << "    " << Att << "    " << AttG << "    "
        << Cmp << "    " << Pct << "    " << Yds << "    " << YdsG << "    " << Lng << "    " << TD << "    " << Int << "    "
        << Sck << "    " << SckYL << "    " << Rating;
   if (Next != NULL)
      Next->print();
}
//----------------------------------------------
// Main program
//----------------------------------------------
int main()
{
   Node list;
   if (list.readData())
      cout << "Success" << endl;
   else
      cout << "Fail" << endl;
   return 0;
}

在您的文件中,有Charlie Batch等等。当你读到它时,你认为会发生什么?名称将变为Charlie;位置将变为CCD_ 5。

之所以会发生这种情况,是因为在满足空白之前都会读取数据。

http://cplusplus.com/reference/fstream/fstream/?kw=fstream

你试过启动循环吗?获取文件的第一行,然后执行while语句。在while语句中,创建新节点,然后获取下一行。在那里结束循环的代码块。

// Read data
Node *head = NULL;
  din >> name >> position >> team >> g >> att >> attg >> cmp >> pct >> yds >> ydsg >> lng >> td >> inte >> sck >> sckyl >> rating;
while (!din.eof())
{
  Node *temp = new Node(name, position, team, g, att, attg, cmp, pct, yds, ydsg, lng, td, inte, sck, sckyl, rating);
  temp->setNext(head);
  head = temp;
  din >> name >> position >> team >> g >> att >> attg >> cmp >> pct >> yds >> ydsg >> lng >> td >> inte >> sck >> sckyl >> rating;
}