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Tell me how to do : Correct cin,cout from file.

hentaiw (273)
.Write a program that will correct a C++ program that has errors in which operator, << or
>>, it uses with cin and cout. The program replaces each (incorrect) occurrence of
cin <<
with the corrected version
cin >>
and each (incorrect) occurrence of
cout >>
with the corrected version
cout <<


You don't have to write code,but tell me how to start.I need your help.
Moschops (7244)
Open bad text file
Copy entire thing to new file, replacing "cin <<" with "cin >>" and similarly for cout errors.
Delete original bad text file
rename new one to have name of the deleted one
hentaiw (273)
No but the algorithm,not these basic steps...

I made it but it ridiculously buggy...somehow dangerous...

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#include <iostream>
#include <fstream>
#include <cstdlib>
#include <cmath>
#include <string>
#include <iomanip>
#include <cstring>

using std::exit;
using std::cin;
using std::cout;
using std::ostream;
using std::istream;
using std::ifstream;
using std::ofstream;
using std::endl;
using std::pow;
using std::sqrt;
using std::getline;
using std::string;
using std::ios;
using std::setw;

const void correct(ifstream& fin,ofstream& fout);
//Pre : fs1 & fs2 must exist,fs3 optional
//Post : merge from fs1 and fs2 to fs3,then sort

int main()
{
	ifstream fin;
	ofstream fout;

	cout << "AverageLengthFromFile - By Kudy" << endl;

	fin.open("cincoutbef.txt");

	if(fin.fail())
	{
		cout << "Fin.Fail()";
		exit(1);
	}

	fout.open("cincoutaft.txt");

	if(fout.fail())
	{
		cout << "Fout.Fail()";
		exit(1);
	}

	correct(fin,fout);

	fin.close();
	fout.close();

	return 0;
}

const void correct(ifstream& fin,ofstream& fout)
{
	char next;
	cout << "CinCoutCorrection - By Kudy" << endl;
	fin.get(next);
	while(!fin.eof())
	{
		if(next == 'c')
		{
			fin.get(next);
			if(next == 'i')
			{
				fin.get(next);
				if(next == 'n')
				{
					fin >> next;
					if(next == '<')
					{
						fin >> next;
						if(next == '<')
						{
							fout << "cin >>";
							fin.get(next);
						}
						else
						{
							fout << "cin >" << next;
							fin.get(next);
						}
					}
					else
					{
						fout << "cin " << next;
						fin.get(next);
					}
				}
				else
				{
					fout << "ci" << next;
					fin.get(next);
				}
			}
			else if(next == 'o')
			{
				fin.get(next);
				if(next == 'u')
				{
					fin.get(next);
					if(next == 't')
					{
						fin >> next;
						if(next == '>')
						{
							fin.get(next);
							if(next == '>')
							{
								fout << "cout <<";
								fin.get(next);
							}
							else
							{
								fout << "cout >" << next;
							}
						}
						else
						{
							fout << "cout " << next;
							fin.get(next);
						}
					}
					else
					{
						fout << "cou" << next;
						fin.get(next);
					}
				}
				else
				{
					fout << "co" << next;
					fin.get(next);
				}
			}
			else
			{
				fout << "c" << next;
				fin.get(next);
			}
		}
		else
		{
			fout << next;
			fin.get(next);
		}
	}
}



I'd like to know a better way to do this task.
Last edited on
andywestken (4094)
You could recode your correct routine using a line-based approach (using std::getline and std::string's replace method)

Andy
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