Merging Two Files using C++

Is there a simple way of merging File1 and File2 into OutFile without the use of arrays, only using fstream?

File1:
111 Joe Smith
333 Steve Smith
555 Ron Smith

File2:
222 Don Smith
444 Randy Smith

OutFile:
111 Joe Smith
222 Randy Smith
333 Steve Smith
444 Randy Smith
555 Ron Smith

Why don't you want to use arrays? (I can't think of any other way)

Unfortunately to make my life more difficult I was told not to. This is the code I have so far:

Code:

---

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
        ifstream File1;
        ifstream File2;
        ofstream outFile;

        string File1_fName, File1_lName;
        string File2_fName, File2_lName;
        int File1_acctNum, File2_acctNum;

        File1.open("file1", ios::in);
        File2.open("file2", ios::in);
        outFile.open("out.txt", ios::out);

        File1 >> File1_acctNum >> File1_fName >> File1_lName;
        File2 >> File2_acctNum >> File2_fName >> File2_lName;
        while (!File1.eof() && !File2.eof())
        {
                if (File2_acctNum > File1_acctNum)
                {
                        outFile << File1_acctNum << '\t' << File1_fName << '\t'
                                << File1_lName << " *\n";
                        outFile << File2_acctNum << '\t' << File2_fName << '\t'
                                << File2_lName << " *\n";
                        File1 >> File1_acctNum >> File1_fName >> File1_lName;
                        File2 >> File2_acctNum >> File2_fName >> File2_lName;
                        cout << File2_acctNum << "\t" << File2_fName << "\t" << File2_lName << endl;
                }
                else if (File1.eof())
                {
                        while (!File2.eof())
                        {
                                outFile << File2_acctNum << '\t' << File2_fName << '\t'
                                        << File2_lName << '\n';
                        }
                }
                else if (File2.eof())
                {
                        while(!File1.eof())
                        {
                                outFile << File1_acctNum << '\t' << File1_fName << '\t'
                                        << File1_lName << '\n';
                        }
                }

        }
        return 0;
}

---

Absolutely it's possible. The algorithm is pretty simple. here's a psuedcode example.

Code:

---

// read a line from reach file (file a, file b)
storedA = a.readline();
storedB = b.readline();
 
// loop until one of the files is empty
while(!a.eof() && !b.eof())
{
  // if a comes before b, write it, and read the next line from A.
  // loop until this next line doesn't come before line B
  while(storedA comes before storedB)
  {
      write(storedA);
      storedA = a.readline();
  }
 
  // repeat the process for B < A.
  while(storedB comes before storedA)
  {
      write(storedB);
      storedB = b.readline();
  }
 
}

// here check if either of the files has reached End Of File.
// if true, write the rest of the other file.

---

You probably need to check for EOF inside each of the inner while loops, but I left that out. Good luck!

Don't use eof() in loop conditions. Directly check the stream objects.