C++文件讀取和拆分列

Question

我不熟悉C++文件讀取，但我通過pyspark做了很多。 所以現在我有一個txt文件，該文件內容如下：

1 52 Hayden Smith  18:16 15 M Berlin 

2 54 Mark Puleo  18:25 15 M Berlin 

3 97 Peter Warrington 18:26 29 M New haven 

4 305 Matt Kasprzak  18:53 33 M Falls Church 

5 272 Kevin Solar  19:17 16 M Sterling 

6 394 Daniel Sullivan  19:35 26 M Sterling 

7 42 Kevan DuPont  19:58 18 M Boylston 

8 306 Chris Goethert  20:00 43 M Falls Church 

正如你可以看到有8列和351列（其中我只顯示8行）， 對於每一行，[0 ]是排名，[1]是BIB，[2]是名，[3]是姓，[4]是時間，[5]是年齡，[6]是性別，[7]是城鎮 例如，第一排，第一排名，第52名BIB，海登史密斯名，18:16是時間，15歲，M是男性，柏林是小鎮。

我有一個排序的鏈接結構，我們稱之爲：類SortedLinked 和項目類型類，叫做：類亞軍

你不必擔心SortedLinked類。

級亞軍有四個私有屬性：

string name, int age, int min, int sec 

在我的驅動程序文件，我可以這樣做：

SortedLinked mylist     // initialize a sorted list 

Runner M("Jordan", 22, 20, 20)  // initialize a Runner called Jordan, who is 22 years old, and finished the race in 20 mins and 20 sec 

mylist.add(M) //add Runner M into my sorted list 

所以我需要閱讀的文本文件，並創建一個亞軍對象跑步者的名字，年齡，分鐘數和秒數。將該Runner插入到已排序的鏈接列表中。

因此，如果這是在pyspark，我可以做到這一點：

file=sc.textFile("hdfs")    //we usually use hdfs in pyspark 

newfile = file.map(lambda line: line.split('\t') //for each column, they are seperated by Tabs, except column[2][3] are separated by a space 

ColumnIneed = newfile.filter(lambda r: [r[2], r[3], r[4], r[5]]) // I only need the column [2][3][4][5] 

mylist = ColumnIneed.collect() // transform the RDD into a list 

Then I can just transform every row into a Runner object. 

，但在C++中，我只知道這一點：

ifstream, infile; 

string s, sAll; 

if(infile.is_open()) 
{ 

    while(getline(line, s)) 

    { 

     s = s.rstrip('\n')  //does NOT work in C++ 
     name, age, time = s.split('\t') // Does NOT work in C++ and I dont need all the columns 

SO，提出問題：

1，我需要訪問每一行，並且去掉換行符

2，我只需要列[2] [3] [4] [5] //每列是s通過標籤eparated

3，柱[4]是時間，這是字符串中的文本文件，我需要拆分 「：」 並投入mintues和秒

4，柱[2] [3]是姓氏和名字，我需要將它們組合成字符串名稱

5，列[2] [3]由空格

分離，理想情況下，我想這樣做：

while(I need a loop) 
{ 

    eachline = access each line; 

    eachline.strip('\n') //strip newline 

    eachline.split('\t') //split Tabs 

    string name = eachline[2][3]; 

    string time = eachline[4]; 

    int min; 

    int sec; 

    min, sec = time.split(':") 

    int age = eachline[5]; 

    Runner M(name, age, min, sec) //I don't know if this works, because it looks like you are overwriting the Runner M each time you access a new line. 

    mylist.add(M)  //add M into my linkedlist, this step you don't need to worry, I already finished. 

} 

如果你有更好的方法做的，我真的很感激它。

Answer 1

一些代碼片斷

std::ifstream in; 
    in.open(/*path to file*/); 
    std::string line; 
    if(in.is_open()) 
    { 
     while(std::getline(in, line)) //get 1 row as a string 
     { 
      std::istringstream iss(line); //put line into stringstream 
      std::string word; 
      while(iss >> word) //read word by word 
      { 
       std::cout << word << std::endl; 
      } 
      /* 
      int row; 
      int age; 
      std::string name; 
      iss >> row >> age >> name; // adopt to your input line 
      Runner M(name, age, min, sec); //common agreement - variables shouldn't start with capital, you don't override M, each time u create new local variable type of Runner, then you put copy of M into some container, M gets destroyed at the end of the block, probably you could use movement semantic, but you need C++ basics first  
      mylist.add(M); 
      */ 
     } 
    }